diff --git a/.ci/make_and_test.sh b/.ci/make_and_test.sh
index af8de340..07df22e8 100755
--- a/.ci/make_and_test.sh
+++ b/.ci/make_and_test.sh
@@ -1,14 +1,14 @@
 #!/usr/bin/env bash
 echo -en "travis_fold:start:script.build\\r"
 echo "Building..."
-STD=$1
+STD="$1"
 shift
 set -evx
 
 
 mkdir -p build
 cd build
-cmake .. -DCLI11_WARNINGS_AS_ERRORS=ON -DCLI11_SINGLE_FILE=ON -DCMAKE_CXX_STANDARD=$STD -DCLI11_SINGLE_FILE_TESTS=ON -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER_LAUNCHER=ccache $@
+cmake .. -DCLI11_WARNINGS_AS_ERRORS=ON -DCLI11_SINGLE_FILE=ON -DCMAKE_CXX_STANDARD="$STD" -DCLI11_SINGLE_FILE_TESTS=ON -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER_LAUNCHER=ccache $@
 cmake --build . -- -j2
 
 set +evx
diff --git a/.ci/run_codecov.sh b/.ci/run_codecov.sh
index 28d149a5..fbc199ca 100755
--- a/.ci/run_codecov.sh
+++ b/.ci/run_codecov.sh
@@ -4,7 +4,7 @@ echo -en "travis_fold:start:script.build\\r"
 echo "Building..."
 set -evx
 
-cd ${TRAVIS_BUILD_DIR}
+cd "${TRAVIS_BUILD_DIR}"
 mkdir -p build
 cd build
 cmake .. -DCLI11_SINGLE_FILE_TESTS=OFF -DCLI11_EXAMPLES=OFF -DCMAKE_BUILD_TYPE=Coverage
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 263dd70f..9121109c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -178,28 +178,28 @@ configuration options were added to facilitate a wider variety of apps.  GCC
 
 Set handling has been completely replaced by a new backend that works as a Validator or Transformer. This provides a single interface instead of the 16 different functions in App. It also allows ordered collections to be used, custom functions for filtering, and better help and error messages. You can also use a collection of pairs (like `std::map`) to transform the match into an output. Also new are inverted flags, which can cancel or reduce the count of flags, and can also support general flag types. A new `add_option_fn` lets you more easily program CLI11 options with the types you choose. Vector options now support a custom separator. Apps can now be composed with unnamed subcommand support. The final bool "defaults" flag when creating options has been replaced by `->capture_default_str()` (ending an old limitation in construction made this possible); the old method is still available but may be removed in future versions.
 
-* Replaced default help capture: `.add_option("name", value, "", True)` becomes `.add_option("name", value)->capture_default_str()` [#242]
-* Added `.always_capture_default()` [#242]
-* New `CLI::IsMember` validator replaces set validation [#222]
-* IsMember also supports container of pairs, transform allows modification of result [#228]
-* Added new Transformers, `CLI::AsNumberWithUnit` and `CLI::AsSizeValue` [#253]
-* Much more powerful flags with different values [#211], general types [#235]
-* `add_option` now supports bool due to unified bool handling [#211]
-* Support for composable unnamed subcommands [#216]
-* Reparsing is better supported with `.remaining_for_passthrough()` [#265]
-* Custom vector separator using `->delimiter(char)` [#209], [#221], [#240]
-* Validators added for IP4 addresses and positive numbers [#210] and numbers [#262]
-* Minimum required Boost for optional Optionals has been corrected to 1.61 [#226]
-* Positionals can stop options from being parsed with `app.positionals_at_end()` [#223]
-* Added `validate_positionals` [#262]
-* Positional parsing is much more powerful [#251], duplicates supported []#247]
-* Validators can be negated with `!` [#230], and now handle tname functions [#228]
-* Better enum support and streaming helper [#233] and [#228]
-* Cleanup for shadow warnings [#232]
-* Better alignment on multiline descriptions [#269]
-* Better support for aarch64 [#266]
-* Respect `BUILD_TESTING` only if CLI11 is the main project; otherwise, `CLI11_TESTING` must be used [#277]
-* Drop auto-detection of experimental optional and boost::optional; must be enabled explicitly (too fragile) [#277] [#279]
+* Replaced default help capture: `.add_option("name", value, "", True)` becomes `.add_option("name", value)->capture_default_str()` [#242][]
+* Added `.always_capture_default()` [#242][]
+* New `CLI::IsMember` validator replaces set validation [#222][]
+* `IsMember` also supports container of pairs, transform allows modification of result [#228][]
+* Added new Transformers, `CLI::AsNumberWithUnit` and `CLI::AsSizeValue` [#253][]
+* Much more powerful flags with different values [#211][], general types [#235][]
+* `add_option` now supports bool due to unified bool handling [#211][]
+* Support for composable unnamed subcommands [#216][]
+* Reparsing is better supported with `.remaining_for_passthrough()` [#265][]
+* Custom vector separator using `->delimiter(char)` [#209][], [#221][], [#240][]
+* Validators added for IP4 addresses and positive numbers [#210] and numbers [#262][]
+* Minimum required Boost for optional Optionals has been corrected to 1.61 [#226][]
+* Positionals can stop options from being parsed with `app.positionals_at_end()` [#223][]
+* Added `validate_positionals` [#262][]
+* Positional parsing is much more powerful [#251][], duplicates supported [#247][]
+* Validators can be negated with `!` [#230][], and now handle tname functions [#228][]
+* Better enum support and streaming helper [#233][] and [#228][]
+* Cleanup for shadow warnings [#232][]
+* Better alignment on multiline descriptions [#269][]
+* Better support for aarch64 [#266][]
+* Respect `BUILD_TESTING` only if CLI11 is the main project; otherwise, `CLI11_TESTING` must be used [#277][]
+* Drop auto-detection of experimental optional and boost::optional; must be enabled explicitly (too fragile) [#277][] [#279][]
 
 > ### Converting from CLI11 1.7:
 >
@@ -243,9 +243,9 @@ Set handling has been completely replaced by a new backend that works as a Valid
 This version provides a quick patch for a (correct) warning from GCC 8 for the windows options code.
 
 
-* Fix for Windows style option parsing [#201]
-* Improve `add_subcommand` when throwing an exception [#204]
-* Better metadata for Conan package [#202]
+* Fix for Windows style option parsing [#201][]
+* Improve `add_subcommand` when throwing an exception [#204][]
+* Better metadata for Conan package [#202][]
 
 [#201]: https://github.com/CLIUtils/CLI11/pull/201
 [#202]: https://github.com/CLIUtils/CLI11/pull/202
@@ -256,20 +256,20 @@ This version provides a quick patch for a (correct) warning from GCC 8 for the w
 The parsing procedure now maps much more sensibly to complex, nested subcommand structures. Each phase of the parsing happens on all subcommands before moving on with the next phase of the parse. This allows several features, like required environment variables, to work properly even through subcommand boundaries.
 Passing the same subcommand multiple times is better supported. Several new features were added as well, including Windows style option support, parsing strings directly, and ignoring underscores in names. Adding a set that you plan to change later must now be done with `add_mutable_set`.
 
-* Support Windows style options with `->allow_windows_style_options`. [#187] On by default on Windows. [#190]
-* Added `parse(string)` to split up and parse a command-line style string directly. [#186]
-* Added `ignore_underscore` and related functions, to ignore underscores when matching names. [#185]
-* The default INI Config will now add quotes to strings with spaces [#195]
-* The default message now will mention the help-all flag also if present [#197]
-* Added `->description` to set Option descriptions [#199]
-* Mutating sets (introduced in Version 1.6) now have a clear add method, `add_mutable_set*`, since the set reference should not expire [#200]
-* Subcommands now track how many times they were parsed in a parsing process. `count()` with no arguments will return the number of times a subcommand was encountered. [#179]
-* Parsing is now done in phases: `shortcurcuits`, `ini`, `env`, `callbacks`, and `requirements`; all subcommands complete a phase before moving on. [#179]
-* Calling parse multiple times is now officially supported without `clear` (automatic). [#179]
-* Dropped the mostly undocumented `short_circuit` property, as help flag parsing is a bit more complex, and the default callback behavior of options now works properly. [#179]
-* Use the standard `BUILD_TESTING` over `CLI11_TESTING` if defined [#183]
-* Cleanup warnings [#191]
-* Remove deprecated names: `set_footer`, `set_name`, `set_callback`, and `set_type_name`. Use without the `set_` instead. [#192]
+* Support Windows style options with `->allow_windows_style_options`. [#187][] On by default on Windows. [#190][]
+* Added `parse(string)` to split up and parse a command-line style string directly. [#186][]
+* Added `ignore_underscore` and related functions, to ignore underscores when matching names. [#185][]
+* The default INI Config will now add quotes to strings with spaces [#195][]
+* The default message now will mention the help-all flag also if present [#197][]
+* Added `->description` to set Option descriptions [#199][]
+* Mutating sets (introduced in Version 1.6) now have a clear add method, `add_mutable_set*`, since the set reference should not expire [#200][]
+* Subcommands now track how many times they were parsed in a parsing process. `count()` with no arguments will return the number of times a subcommand was encountered. [#179][]
+* Parsing is now done in phases: `shortcurcuits`, `ini`, `env`, `callbacks`, and `requirements`; all subcommands complete a phase before moving on. [#179][]
+* Calling parse multiple times is now officially supported without `clear` (automatic). [#179][]
+* Dropped the mostly undocumented `short_circuit` property, as help flag parsing is a bit more complex, and the default callback behavior of options now works properly. [#179][]
+* Use the standard `BUILD_TESTING` over `CLI11_TESTING` if defined [#183][]
+* Cleanup warnings [#191][]
+* Remove deprecated names: `set_footer`, `set_name`, `set_callback`, and `set_type_name`. Use without the `set_` instead. [#192][]
 
 > ### Converting from CLI11 1.6:
 >
@@ -294,17 +294,17 @@ Passing the same subcommand multiple times is better supported. Several new feat
 
 This version fixes some formatting bugs with help-all. It also adds fixes for several warnings, including an experimental optional error on Clang 7. Several smaller fixes.
 
-* Fixed help-all formatting [#163]
+* Fixed help-all formatting [#163][]
     * Printing help-all on nested command now fixed (App)
     * Missing space after help-all restored (Default formatter)
     * More detail printed on help all (Default formatter)
     * Help-all subcommands get indented with inner blank lines removed (Default formatter)
     * `detail::find_and_replace` added to utilities
-* Fixed CMake install as subproject with `CLI11_INSTALL` flag. [#156]
-* Fixed warning about local variable hiding class member with MSVC [#157]
-* Fixed compile error with default settings on Clang 7 and libc++ [#158]
-* Fixed special case of `--help` on subcommands (general fix planned for 1.7) [#168]
-* Removing an option with links  [#179]
+* Fixed CMake install as subproject with `CLI11_INSTALL` flag. [#156][]
+* Fixed warning about local variable hiding class member with MSVC [#157][]
+* Fixed compile error with default settings on Clang 7 and libc++ [#158][]
+* Fixed special case of `--help` on subcommands (general fix planned for 1.7) [#168][]
+* Removing an option with links  [#179][]
 
 [#156]: https://github.com/CLIUtils/CLI11/issues/156
 [#157]: https://github.com/CLIUtils/CLI11/issues/157
@@ -320,9 +320,9 @@ This version provides a few fixes for special cases, such as mixing with `Window
 for systems like Hunter. The one new feature is the ability to produce "branded" single file output for
 providing custom namespaces or custom macro names.
 
-* Added fix and test for including Windows.h [#145]
-* No longer build single file by default if main project, supports systems stuck on Python 2.6 [#149], [#151]
-* Branding support for single file output [#150]
+* Added fix and test for including Windows.h [#145][]
+* No longer build single file by default if main project, supports systems stuck on Python 2.6 [#149][], [#151][]
+* Branding support for single file output [#150][]
 
 [#145]: https://github.com/CLIUtils/CLI11/pull/145
 [#149]: https://github.com/CLIUtils/CLI11/pull/149
@@ -331,7 +331,7 @@ providing custom namespaces or custom macro names.
 
 ## Version 1.6: Formatting help
 
-Added a new formatting system [#109]. You can now set the formatter on Apps. This has also simplified the internals of Apps and Options a bit by separating most formatting code.
+Added a new formatting system [#109][]. You can now set the formatter on Apps. This has also simplified the internals of Apps and Options a bit by separating most formatting code.
 
 * Added `CLI::Formatter` and `formatter` slot for apps, inherited.
 * `FormatterBase` is the minimum required.
@@ -347,10 +347,10 @@ Changes to the help system (most normal users will not notice this):
 * Protected function `_has_help_positional` removed.
 * `format_help` can now be chained.
 * Added getters for the missing parts of options (help no longer uses any private parts).
-* Help flags now use new `short_circuit` property to simplify parsing. [#121]
+* Help flags now use new `short_circuit` property to simplify parsing. [#121][]
 
 
-New for Config file reading and writing [#121]:
+New for Config file reading and writing [#121][]:
 
 * Overridable, bidirectional Config.
 * ConfigINI provided and used by default.
@@ -361,7 +361,7 @@ New for Config file reading and writing [#121]:
 * Added an example of a custom config format using [nlohmann/json]. [#138]
 
 
-Validators are now much more powerful [#118], all built in validators upgraded to the new form:
+Validators are now much more powerful [#118][], all built in validators upgraded to the new form:
 
 * A subclass of `CLI::Validator` is now also accepted.
 * They now can set the type name to things like `PATH` and `INT in [1-4]`.
@@ -370,29 +370,29 @@ Validators are now much more powerful [#118], all built in validators upgraded t
 
 Other changes:
 
-* Fixing `parse(args)`'s `args` setting and ordering after parse. [#141]
-* Replaced `set_custom_option` with `type_name` and `type_size` instead of `set_custom_option`. Methods return `this`. [#136]
-* Dropped `set_` on Option's `type_name`, `default_str`, and `default_val`. [#136]
-* Removed `set_` from App's `failure_message`, `footer`, `callback`, and `name`. [#136]
-* Fixed support `N<-1` for `type_size`. [#140]
-* Added `->each()` to make adding custom callbacks easier. [#126]
-* Allow empty options `add_option("-n",{})` to be edited later with `each` [#142]
+* Fixing `parse(args)`'s `args` setting and ordering after parse. [#141][]
+* Replaced `set_custom_option` with `type_name` and `type_size` instead of `set_custom_option`. Methods return `this`. [#136][]
+* Dropped `set_` on Option's `type_name`, `default_str`, and `default_val`. [#136][]
+* Removed `set_` from App's `failure_message`, `footer`, `callback`, and `name`. [#136][]
+* Fixed support `N<-1` for `type_size`. [#140][]
+* Added `->each()` to make adding custom callbacks easier. [#126][]
+* Allow empty options `add_option("-n",{})` to be edited later with `each` [#142][]
 * Added filter argument to `get_subcommands`, `get_options`; use empty filter `{}` to avoid filtering.
 * Added `get_groups()` to get groups.
-* Better support for manual options with `get_option`, `set_results`, and `empty`. [#119]
-* `lname` and `sname` have getters, added `const get_parent`. [#120]
-* Using `add_set` will now capture L-values for sets, allowing further modification. [#113]
+* Better support for manual options with `get_option`, `set_results`, and `empty`. [#119][]
+* `lname` and `sname` have getters, added `const get_parent`. [#120][]
+* Using `add_set` will now capture L-values for sets, allowing further modification. [#113][]
 * Dropped duplicate way to run `get_type_name` (`get_typeval`).
-* Removed `requires` in favor of `needs` (deprecated in last version). [#112]
-* Const added to argv. [#126]
+* Removed `requires` in favor of `needs` (deprecated in last version). [#112][]
+* Const added to argv. [#126][]
 
 Backend and testing changes:
 
-* Internally, `type_name` is now a lambda function; for sets, this reads the set live. [#116]
-* Cleaner tests without `app.reset()` (and `reset` is now `clear`). [#141]
-* Better CMake policy handling. [#110]
-* Includes are properly sorted. [#120]
-* Testing (only) now uses submodules. [#111]
+* Internally, `type_name` is now a lambda function; for sets, this reads the set live. [#116][]
+* Cleaner tests without `app.reset()` (and `reset` is now `clear`). [#141][]
+* Better CMake policy handling. [#110][]
+* Includes are properly sorted. [#120][]
+* Testing (only) now uses submodules. [#111][]
 
 [#109]: https://github.com/CLIUtils/CLI11/pull/109
 [#110]: https://github.com/CLIUtils/CLI11/pull/110
@@ -427,13 +427,13 @@ This is a quick patch release that makes LICENSE part of the single header file,
 
 This patch release adds better access to the App programmatically, to assist with writing custom converters to other formats. It also improves the help output, and uses a new feature in CLI11 1.5 to fix an old "quirk" in the way unlimited options and positionals interact.
 
-* Make mixing unlimited positionals and options more intuitive [#102]
-* Add missing getters `get_options` and `get_description` to App [#105]
-* The app name now can be set, and will override the auto name if present [#105]
-* Add `(REQUIRED)` for required options [#104]
-* Print simple name for Needs/Excludes [#104]
-* Use Needs instead of Requires in help print [#104]
-* Groups now are listed in the original definition order [#106]
+* Make mixing unlimited positionals and options more intuitive [#102][]
+* Add missing getters `get_options` and `get_description` to App [#105][]
+* The app name now can be set, and will override the auto name if present [#105][]
+* Add `(REQUIRED)` for required options [#104][]
+* Print simple name for Needs/Excludes [#104][]
+* Use Needs instead of Requires in help print [#104][]
+* Groups now are listed in the original definition order [#106][]
 
 [#102]: https://github.com/CLIUtils/CLI11/issues/102
 [#104]: https://github.com/CLIUtils/CLI11/pull/104
@@ -447,21 +447,21 @@ This version introduced support for optionals, along with clarification and exam
 
 Note: This is the final release with `requires`, please switch to `needs`.
 
-* Fix unlimited short options eating two values before checking for positionals when no space present [#90]
-* Symmetric exclude text when excluding options, exclude can be called multiple times [#64]
-* Support for `std::optional`, `std::experimental::optional`, and `boost::optional` added if `__has_include` is supported [#95]
-* All macros/CMake variables now start with `CLI11_` instead of just `CLI_` [#95]
-* The internal stream was not being cleared before use in some cases. Fixed. [#95]
-* Using an enum now requires explicit conversion overload [#97]
-* The separator `--` now is removed when it ends unlimited arguments [#100]
+* Fix unlimited short options eating two values before checking for positionals when no space present [#90][]
+* Symmetric exclude text when excluding options, exclude can be called multiple times [#64][]
+* Support for `std::optional`, `std::experimental::optional`, and `boost::optional` added if `__has_include` is supported [#95][]
+* All macros/CMake variables now start with `CLI11_` instead of just `CLI_` [#95][]
+* The internal stream was not being cleared before use in some cases. Fixed. [#95][]
+* Using an enum now requires explicit conversion overload [#97][]
+* The separator `--` now is removed when it ends unlimited arguments [#100][]
 
 Other, non-user facing changes:
 
-* Added `Macros.hpp` with better C++ mode discovery [#95]
+* Added `Macros.hpp` with better C++ mode discovery [#95][]
 * Deprecated macros added for all platforms
-* C++17 is now tested on supported platforms [#95]
-* Informational printout now added to CTest [#95]
-* Better single file generation [#95]
+* C++17 is now tested on supported platforms [#95][]
+* Informational printout now added to CTest [#95][]
+* Better single file generation [#95][]
 * Added support for GTest on MSVC 2017 (but not in C++17 mode, will need next version of GTest)
 * Types now have a specific size, separate from the expected number - cleaner and more powerful internally [#92]
 * Examples now run as part of testing [#99]
@@ -479,17 +479,17 @@ Other, non-user facing changes:
 
 This version adds lots of smaller fixes and additions after the refactor in version 1.3. More ways to download and use CLI11 in CMake have been added. INI files have improved support.
 
-* Lexical cast is now more strict than before [#68] and fails on overflow [#84]
+* Lexical cast is now more strict than before [#68] and fails on overflow [#84][]
 * Added `get_parent()` to access the parent from a subcommand
-* Added `ExistingPath` validator  [#73]
-* `app.allow_ini_extras()` added to allow extras in INI files [#70]
+* Added `ExistingPath` validator  [#73][]
+* `app.allow_ini_extras()` added to allow extras in INI files [#70][]
 * Multiline INI comments now supported
-* Descriptions can now be written with `config_to_str` [#66]
-* Double printing of error message fixed [#77]
-* Renamed `requires` to `needs` to avoid C++20 keyword [#75], [#82]
-* MakeSingleHeader now works if outside of git [#78]
-* Adding install support for CMake [#79], improved support for `find_package` [#83], [#84]
-* Added support for Conan.io [#83]
+* Descriptions can now be written with `config_to_str` [#66][]
+* Double printing of error message fixed [#77][]
+* Renamed `requires` to `needs` to avoid C++20 keyword [#75][], [#82][]
+* MakeSingleHeader now works if outside of git [#78][]
+* Adding install support for CMake [#79][], improved support for `find_package` [#83][], [#84][]
+* Added support for Conan.io [#83][]
 
 [#70]: https://github.com/CLIUtils/CLI11/issues/70
 [#75]: https://github.com/CLIUtils/CLI11/issues/75
diff --git a/CLI11.hpp.in b/CLI11.hpp.in
index 7a3b0b9b..9439a430 100644
--- a/CLI11.hpp.in
+++ b/CLI11.hpp.in
@@ -5,7 +5,7 @@
 // This is a standalone header file generated by MakeSingleHeader.py in CLI11/scripts
 // from: {git}
 //
-// CLI11 {version} Copyright (c) 2017-2020 University of Cincinnati, developed by Henry
+// CLI11 {version} Copyright (c) 2017-2021 University of Cincinnati, developed by Henry
 // Schreiner under NSF AWARD 1414736. All rights reserved.
 //
 // Redistribution and use in source and binary forms of CLI11, with or without
diff --git a/README.md b/README.md
index a67c931a..75137d63 100644
--- a/README.md
+++ b/README.md
@@ -24,38 +24,38 @@ CLI11 is a command line parser for C++11 and beyond that provides a rich feature
 
 ## Table of Contents
 
--   [Background](#background)
-    -   [Introduction](#introduction)
-    -   [Why write another CLI parser?](#why-write-another-cli-parser)
-    -   [Other parsers](#other-parsers)
-    -   [Features not supported by this library](#features-not-supported-by-this-library)
--   [Install](#install)
--   [Usage](#usage)
-    -   [Adding options](#adding-options)
-        -   [Option types](#option-types)
-        -   [Example](#example)
-        -   [Option options](#option-options)
-        -   [Validators](#validators)
-            -   [Transforming Validators](#transforming-validators)
-            -   [Validator operations](#validator-operations)
-            -   [Custom Validators](#custom-validators)
-            -   [Querying Validators](#querying-validators)
-        -   [Getting Results](#getting-results)
-    -   [Subcommands](#subcommands)
-        -   [Subcommand options](#subcommand-options)
-        -   [Option groups](#option-groups)
-        -   [Callbacks](#callbacks)
-    -   [Configuration file](#configuration-file)
-    -   [Inheriting defaults](#inheriting-defaults)
-    -   [Formatting](#formatting)
-    -   [Subclassing](#subclassing)
-    -   [How it works](#how-it-works)
-    -   [Utilities](#utilities)
-    -   [Other libraries](#other-libraries)
--   [API](#api)
--   [Examples](#Examples)
--   [Contribute](#contribute)
--   [License](#license)
+- [Background](#background)
+    - [Introduction](#introduction)
+    - [Why write another CLI parser?](#why-write-another-cli-parser)
+    - [Other parsers](#other-parsers)
+    - [Features not supported by this library](#features-not-supported-by-this-library)
+- [Install](#install)
+- [Usage](#usage)
+    - [Adding options](#adding-options)
+        - [Option types](#option-types)
+        - [Example](#example)
+        - [Option options](#option-options)
+        - [Validators](#validators)
+            - [Transforming Validators](#transforming-validators)
+            - [Validator operations](#validator-operations)
+            - [Custom Validators](#custom-validators)
+            - [Querying Validators](#querying-validators)
+        - [Getting Results](#getting-results)
+    - [Subcommands](#subcommands)
+        - [Subcommand options](#subcommand-options)
+        - [Option groups](#option-groups)
+        - [Callbacks](#callbacks)
+    - [Configuration file](#configuration-file)
+    - [Inheriting defaults](#inheriting-defaults)
+    - [Formatting](#formatting)
+    - [Subclassing](#subclassing)
+    - [How it works](#how-it-works)
+    - [Utilities](#utilities)
+    - [Other libraries](#other-libraries)
+- [API](#api)
+- [Examples](#Examples)
+- [Contribute](#contribute)
+- [License](#license)
 
 Features that were added in the last released major version are marked with "🆕". Features only available in master are marked with "🚧".
 
@@ -73,21 +73,21 @@ You can be notified when new releases are made by subscribing to <https://github
 
 An acceptable CLI parser library should be all of the following:
 
--   Easy to include (i.e., header only, one file if possible, **no external requirements**).
--   Short, simple syntax: This is one of the main reasons to use a CLI parser, it should make variables from the command line nearly as easy to define as any other variables. If most of your program is hidden in CLI parsing, this is a problem for readability.
--   C++11 or better: Should work with GCC 4.8+ (default on CentOS/RHEL 7), Clang 3.4+, AppleClang 7+, NVCC 7.0+, or MSVC 2015+.
--   Work on Linux, macOS, and Windows.
--   Well tested using [Travis][] (Linux) and [AppVeyor][] (Windows) or [Azure][] (all three). "Well" is defined as having good coverage measured by [CodeCov][].
--   Clear help printing.
--   Nice error messages.
--   Standard shell idioms supported naturally, like grouping flags, a positional separator, etc.
--   Easy to execute, with help, parse errors, etc. providing correct exit and details.
--   Easy to extend as part of a framework that provides "applications" to users.
--   Usable subcommand syntax, with support for multiple subcommands, nested subcommands, option groups, and optional fallthrough (explained later).
--   Ability to add a configuration file (`TOML`, `INI`, or custom format), and produce it as well.
--   Produce real values that can be used directly in code, not something you have pay compute time to look up, for HPC applications.
--   Work with standard types, simple custom types, and extensible to exotic types.
--   Permissively licensed.
+- Easy to include (i.e., header only, one file if possible, **no external requirements**).
+- Short, simple syntax: This is one of the main reasons to use a CLI parser, it should make variables from the command line nearly as easy to define as any other variables. If most of your program is hidden in CLI parsing, this is a problem for readability.
+- C++11 or better: Should work with GCC 4.8+ (default on CentOS/RHEL 7), Clang 3.4+, AppleClang 7+, NVCC 7.0+, or MSVC 2015+.
+- Work on Linux, macOS, and Windows.
+- Well tested using [Travis][] (Linux) and [AppVeyor][] (Windows) or [Azure][] (all three). "Well" is defined as having good coverage measured by [CodeCov][].
+- Clear help printing.
+- Nice error messages.
+- Standard shell idioms supported naturally, like grouping flags, a positional separator, etc.
+- Easy to execute, with help, parse errors, etc. providing correct exit and details.
+- Easy to extend as part of a framework that provides "applications" to users.
+- Usable subcommand syntax, with support for multiple subcommands, nested subcommands, option groups, and optional fallthrough (explained later).
+- Ability to add a configuration file (`TOML`, `INI`, or custom format), and produce it as well.
+- Produce real values that can be used directly in code, not something you have pay compute time to look up, for HPC applications.
+- Work with standard types, simple custom types, and extensible to exotic types.
+- Permissively licensed.
 
 ### Other parsers
 
@@ -127,10 +127,10 @@ So, this library was designed to provide a great syntax, good compiler compatibi
 
 There are some other possible "features" that are intentionally not supported by this library:
 
--   Non-standard variations on syntax, like `-long` options. This is non-standard and should be avoided, so that is enforced by this library.
--   Completion of partial options, such as Python's `argparse` supplies for incomplete arguments. It's better not to guess. Most third party command line parsers for python actually reimplement command line parsing rather than using argparse because of this perceived design flaw.
--   Autocomplete: This might eventually be added to both Plumbum and CLI11, but it is not supported yet.
--   Wide strings / unicode: Since this uses the standard library only, it might be hard to properly implement, but I would be open to suggestions in how to do this.
+- Non-standard variations on syntax, like `-long` options. This is non-standard and should be avoided, so that is enforced by this library.
+- Completion of partial options, such as Python's `argparse` supplies for incomplete arguments. It's better not to guess. Most third party command line parsers for python actually reimplement command line parsing rather than using argparse because of this perceived design flaw.
+- Autocomplete: This might eventually be added to both Plumbum and CLI11, but it is not supported yet.
+- Wide strings / unicode: Since this uses the standard library only, it might be hard to properly implement, but I would be open to suggestions in how to do this.
 
 ## Install
 
@@ -264,27 +264,33 @@ An option name must start with a alphabetic character, underscore, a number, '?'
 The `add_option_function<type>(...` function will typically require the template parameter be given unless a `std::function` object with an exact match is passed.  The type can be any type supported by the `add_option` function. The function should throw an error (`CLI::ConversionError` or `CLI::ValidationError` possibly) if the value is not valid.
 
 The two parameter template overload can be used in cases where you want to restrict the input such as
-```
+
+```cpp
 double val
 app.add_option<double,unsigned int>("-v",val);
 ```
+
 which would first verify the input is convertible to an `unsigned int` before assigning it.  Or using some variant type
-```
+
+```cpp
 using vtype=std::variant<int, double, std::string>;
  vtype v1;
 app.add_option<vtype,std:string>("--vs",v1);
 app.add_option<vtype,int>("--vi",v1);
 app.add_option<vtype,double>("--vf",v1);
 ```
+
 otherwise the output would default to a string.  The `add_option` can be used with any integral or floating point types, enumerations, or strings.  Or any type that takes an int, double, or std\::string in an assignment operator or constructor.  If an object can take multiple varieties of those, std::string takes precedence, then double then int.    To better control which one is used or to use another type for the underlying conversions use the two parameter template to directly specify the conversion type.
 
 Types such as (std or boost) `optional<int>`, `optional<double>`, and `optional<string>` and any other wrapper types are supported directly. For purposes of CLI11 wrapper types are those which `value_type` definition.  See [CLI11 Advanced Topics/Custom Converters][] for information on how you can add your own converters for additional types.
 
 Vector types can also be used in the two parameter template overload
-```
+
+```cpp
 std::vector<double> v1;
 app.add_option<std::vector<double>,int>("--vs",v1);
 ```
+
 would load a vector of doubles but ensure all values can be represented as integers.
 
 Automatic direct capture of the default string is disabled when using the two parameter template.  Use `set_default_str(...)` or `->default_function(std::string())` to set the default string or capture function directly for these cases.
@@ -314,68 +320,67 @@ On a `C++14` compiler, you can pass a callback function directly to `.add_flag`,
 
 #### Example
 
--   `"one,-o,--one"`: Valid as long as not a flag, would create an option that can be specified positionally, or with `-o` or `--one`
--   `"this"` Can only be passed positionally
--   `"-a,-b,-c"` No limit to the number of non-positional option names
+- `"one,-o,--one"`: Valid as long as not a flag, would create an option that can be specified positionally, or with `-o` or `--one`
+- `"this"` Can only be passed positionally
+- `"-a,-b,-c"` No limit to the number of non-positional option names
 
 The add commands return a pointer to an internally stored `Option`.
 This option can be used directly to check for the count (`->count()`) after parsing to avoid a string based lookup.
-⚠️  Deprecated: The `add_*` commands have a final argument than can be set to true, which causes the default value to be captured and printed on the command line with the help flag. Since CLI11 1.8, you can simply add `->capture_default_str()`.
 
 #### Option options
 
 Before parsing, you can set the following options:
 
--   `->required()`: The program will quit if this option is not present. This is `mandatory` in Plumbum, but required options seems to be a more standard term. For compatibility, `->mandatory()` also works.
--   `->expected(N)`: Take `N` values instead of as many as possible, only for vector args. If negative, require at least `-N`; end with `--` or another recognized option or subcommand.
--   `->type_name(typename)`: Set the name of an Option's type (`type_name_fn` allows a function instead)
--   `->type_size(N)`: Set the intrinsic size of an option. The parser will require multiples of this number if negative.
--   `->needs(opt)`: This option requires another option to also be present, opt is an `Option` pointer.
--   `->excludes(opt)`: This option cannot be given with `opt` present, opt is an `Option` pointer.
--   `->envname(name)`: Gets the value from the environment if present and not passed on the command line.
--   `->group(name)`: The help group to put the option in. No effect for positional options. Defaults to `"Options"`. `""` will not show up in the help print (hidden).
--   `->ignore_case()`: Ignore the case on the command line (also works on subcommands, does not affect arguments).
--   `->ignore_underscore()`: Ignore any underscores in the options names (also works on subcommands, does not affect arguments). For example "option_one" will match with "optionone".  This does not apply to short form options since they only have one character
--   `->disable_flag_override()`: From the command line long form flag options can be assigned a value on the command line using the `=` notation `--flag=value`. If this behavior is not desired, the `disable_flag_override()` disables it and will generate an exception if it is done on the command line.  The `=` does not work with short form flag options.
--   `->allow_extra_args(true/false)`: 🆕 If set to true the option will take an unlimited number of arguments like a vector, if false it will limit the number of arguments to the size of the type used in the option.  Default value depends on the nature of the type use, containers default to true, others default to false.
--   `->delimiter(char)`: Allows specification of a custom delimiter for separating single arguments into vector arguments, for example specifying `->delimiter(',')` on an option would result in `--opt=1,2,3` producing 3 elements of a vector and the equivalent of --opt 1 2 3 assuming opt is a vector value.
--   `->description(str)`: Set/change the description.
--   `->multi_option_policy(CLI::MultiOptionPolicy::Throw)`: Set the multi-option policy. Shortcuts available: `->take_last()`, `->take_first()`,`->take_all()`, and `->join()`. This will only affect options expecting 1 argument or bool flags (which do not inherit their default but always start with a specific policy).
--   `->check(std::string(const std::string &), validator_name="",validator_description="")`: Define a check function.  The function should return a non empty string with the error message if the check fails
--   `->check(Validator)`: Use a Validator object to do the check see [Validators](#validators) for a description of available Validators and how to create new ones.
--   `->transform(std::string(std::string &), validator_name="",validator_description=")`: Converts the input string into the output string, in-place in the parsed options.
--   `->transform(Validator)`: Uses a Validator object to do the transformation see [Validators](#validators) for a description of available Validators and how to create new ones.
--   `->each(void(const std::string &)>`: Run this function on each value received, as it is received. It should throw a `ValidationError` if an error is encountered.
--   `->configurable(false)`: Disable this option from being in a configuration file.
+- `->required()`: The program will quit if this option is not present. This is `mandatory` in Plumbum, but required options seems to be a more standard term. For compatibility, `->mandatory()` also works.
+- `->expected(N)`: Take `N` values instead of as many as possible, only for vector args. If negative, require at least `-N`; end with `--` or another recognized option or subcommand.
+- `->type_name(typename)`: Set the name of an Option's type (`type_name_fn` allows a function instead)
+- `->type_size(N)`: Set the intrinsic size of an option. The parser will require multiples of this number if negative.
+- `->needs(opt)`: This option requires another option to also be present, opt is an `Option` pointer.
+- `->excludes(opt)`: This option cannot be given with `opt` present, opt is an `Option` pointer.
+- `->envname(name)`: Gets the value from the environment if present and not passed on the command line.
+- `->group(name)`: The help group to put the option in. No effect for positional options. Defaults to `"Options"`. `""` will not show up in the help print (hidden).
+- `->ignore_case()`: Ignore the case on the command line (also works on subcommands, does not affect arguments).
+- `->ignore_underscore()`: Ignore any underscores in the options names (also works on subcommands, does not affect arguments). For example "option_one" will match with "optionone".  This does not apply to short form options since they only have one character
+- `->disable_flag_override()`: From the command line long form flag options can be assigned a value on the command line using the `=` notation `--flag=value`. If this behavior is not desired, the `disable_flag_override()` disables it and will generate an exception if it is done on the command line.  The `=` does not work with short form flag options.
+- `->allow_extra_args(true/false)`: 🆕 If set to true the option will take an unlimited number of arguments like a vector, if false it will limit the number of arguments to the size of the type used in the option.  Default value depends on the nature of the type use, containers default to true, others default to false.
+- `->delimiter(char)`: Allows specification of a custom delimiter for separating single arguments into vector arguments, for example specifying `->delimiter(',')` on an option would result in `--opt=1,2,3` producing 3 elements of a vector and the equivalent of --opt 1 2 3 assuming opt is a vector value.
+- `->description(str)`: Set/change the description.
+- `->multi_option_policy(CLI::MultiOptionPolicy::Throw)`: Set the multi-option policy. Shortcuts available: `->take_last()`, `->take_first()`,`->take_all()`, and `->join()`. This will only affect options expecting 1 argument or bool flags (which do not inherit their default but always start with a specific policy).
+- `->check(std::string(const std::string &), validator_name="",validator_description="")`: Define a check function.  The function should return a non empty string with the error message if the check fails
+- `->check(Validator)`: Use a Validator object to do the check see [Validators](#validators) for a description of available Validators and how to create new ones.
+- `->transform(std::string(std::string &), validator_name="",validator_description=")`: Converts the input string into the output string, in-place in the parsed options.
+- `->transform(Validator)`: Uses a Validator object to do the transformation see [Validators](#validators) for a description of available Validators and how to create new ones.
+- `->each(void(const std::string &)>`: Run this function on each value received, as it is received. It should throw a `ValidationError` if an error is encountered.
+- `->configurable(false)`: Disable this option from being in a configuration file.
     `->capture_default_str()`: Store the current value attached and display it in the help string.
--   `->default_function(std::string())`: Advanced: Change the function that `capture_default_str()` uses.
--   `->always_capture_default()`: Always run `capture_default_str()` when creating new options. Only useful on an App's `option_defaults`.
--   `->default_str(string)`:  Set the default string directly.  This string will also be used as a default value if no arguments are passed and the value is requested.
--   `->default_val(value)`: Generate the default string from a value and validate that the value is also valid.  For options that assign directly to a value type the value in that type is also updated.  Value must be convertible to a string(one of known types or have a stream operator).
--   `->option_text(string)`: Sets the text between the option name and description.
+- `->default_function(std::string())`: Advanced: Change the function that `capture_default_str()` uses.
+- `->always_capture_default()`: Always run `capture_default_str()` when creating new options. Only useful on an App's `option_defaults`.
+- `->default_str(string)`:  Set the default string directly.  This string will also be used as a default value if no arguments are passed and the value is requested.
+- `->default_val(value)`: Generate the default string from a value and validate that the value is also valid.  For options that assign directly to a value type the value in that type is also updated.  Value must be convertible to a string(one of known types or have a stream operator).
+- `->option_text(string)`: Sets the text between the option name and description.
 
 
 These options return the `Option` pointer, so you can chain them together, and even skip storing the pointer entirely. The `each` function takes any function that has the signature `void(const std::string&)`; it should throw a `ValidationError` when validation fails. The help message will have the name of the parent option prepended. Since `each`, `check` and `transform` use the same underlying mechanism, you can chain as many as you want, and they will be executed in order. Operations added through `transform` are executed first in reverse order of addition, and `check` and `each` are run following the transform functions in order of addition. If you just want to see the unconverted values, use `.results()` to get the `std::vector<std::string>` of results.
 
 On the command line, options can be given as:
 
--   `-a` (flag)
--   `-abc` (flags can be combined)
--   `-f filename` (option)
--   `-ffilename` (no space required)
--   `-abcf filename` (flags and option can be combined)
--   `--long` (long flag)
--   `--long_flag=true` (long flag with equals to override default value)
--   `--file filename` (space)
--   `--file=filename` (equals)
+- `-a` (flag)
+- `-abc` (flags can be combined)
+- `-f filename` (option)
+- `-ffilename` (no space required)
+- `-abcf filename` (flags and option can be combined)
+- `--long` (long flag)
+- `--long_flag=true` (long flag with equals to override default value)
+- `--file filename` (space)
+- `--file=filename` (equals)
 
 If `allow_windows_style_options()` is specified in the application or subcommand options can also be given as:
--   `/a` (flag)
--   `/f filename` (option)
--   `/long` (long flag)
--   `/file filename` (space)
--   `/file:filename` (colon)
--   `/long_flag:false` (long flag with : to override the default value)
+- `/a` (flag)
+- `/f filename` (option)
+- `/long` (long flag)
+- `/file filename` (space)
+- `/file:filename` (colon)
+- `/long_flag:false` (long flag with : to override the default value)
 =  Windows style options do not allow combining short options or values not separated from the short option like with `-` options
 
 Long flag options may be given with an `=<value>` to allow specifying a false value, or some other value to the flag. See [config files](#configuration-file) for details on the values supported.  NOTE: only the `=` or `:` for windows-style options may be used for this, using a space will result in the argument being interpreted as a positional argument.  This syntax can override the default values, and can be disabled by using `disable_flag_override()`.
@@ -393,22 +398,22 @@ Validators are structures to check or modify inputs, they can be used to verify
 
 CLI11 has several Validators built-in that perform some common checks
 
--   `CLI::IsMember(...)`: Require an option be a member of a given set. See [Transforming Validators](#transforming-validators) for more details.
--   `CLI::Transformer(...)`: Modify the input using a map. See [Transforming Validators](#transforming-validators) for more details.
--   `CLI::CheckedTransformer(...)`: Modify the input using a map, and require that the input is either in the set or already one of the outputs of the set. See [Transforming Validators](#transforming-validators) for more details.
--   `CLI::AsNumberWithUnit(...)`: Modify the `<NUMBER> <UNIT>` pair by matching the unit and multiplying the number by the corresponding factor. It can be used as a base for transformers, that accept things like size values (`1 KB`) or durations (`0.33 ms`).
--   `CLI::AsSizeValue(...)`: Convert inputs like `100b`, `42 KB`, `101 Mb`, `11 Mib` to absolute values. `KB` can be configured to be interpreted as 10^3 or 2^10.
--   `CLI::ExistingFile`: Requires that the file exists if given.
--   `CLI::ExistingDirectory`: Requires that the directory exists.
--   `CLI::ExistingPath`: Requires that the path (file or directory) exists.
--   `CLI::NonexistentPath`: Requires that the path does not exist.
--   `CLI::Range(min,max)`: Requires that the option be between min and max (make sure to use floating point if needed). Min defaults to 0.
--   `CLI::Bounded(min,max)`: Modify the input such that it is always between min and max (make sure to use floating point if needed). Min defaults to 0.  Will produce an error if conversion is not possible.
--   `CLI::PositiveNumber`: Requires the number be greater than 0
--   `CLI::NonNegativeNumber`: Requires the number be greater or equal to 0
--   `CLI::Number`: Requires the input be a number.
--   `CLI::ValidIPV4`: Requires that the option be a valid IPv4 string e.g. `'255.255.255.255'`, `'10.1.1.7'`.
--   `CLI::TypeValidator<TYPE>`:🆕 Requires that the option be convertible to the specified type e.g.  `CLI::TypeValidator<unsigned int>()` would require that the input be convertible to an `unsigned int` regardless of the end conversion.
+- `CLI::IsMember(...)`: Require an option be a member of a given set. See [Transforming Validators](#transforming-validators) for more details.
+- `CLI::Transformer(...)`: Modify the input using a map. See [Transforming Validators](#transforming-validators) for more details.
+- `CLI::CheckedTransformer(...)`: Modify the input using a map, and require that the input is either in the set or already one of the outputs of the set. See [Transforming Validators](#transforming-validators) for more details.
+- `CLI::AsNumberWithUnit(...)`: Modify the `<NUMBER> <UNIT>` pair by matching the unit and multiplying the number by the corresponding factor. It can be used as a base for transformers, that accept things like size values (`1 KB`) or durations (`0.33 ms`).
+- `CLI::AsSizeValue(...)`: Convert inputs like `100b`, `42 KB`, `101 Mb`, `11 Mib` to absolute values. `KB` can be configured to be interpreted as 10^3 or 2^10.
+- `CLI::ExistingFile`: Requires that the file exists if given.
+- `CLI::ExistingDirectory`: Requires that the directory exists.
+- `CLI::ExistingPath`: Requires that the path (file or directory) exists.
+- `CLI::NonexistentPath`: Requires that the path does not exist.
+- `CLI::Range(min,max)`: Requires that the option be between min and max (make sure to use floating point if needed). Min defaults to 0.
+- `CLI::Bounded(min,max)`: Modify the input such that it is always between min and max (make sure to use floating point if needed). Min defaults to 0.  Will produce an error if conversion is not possible.
+- `CLI::PositiveNumber`: Requires the number be greater than 0
+- `CLI::NonNegativeNumber`: Requires the number be greater or equal to 0
+- `CLI::Number`: Requires the input be a number.
+- `CLI::ValidIPV4`: Requires that the option be a valid IPv4 string e.g. `'255.255.255.255'`, `'10.1.1.7'`.
+- `CLI::TypeValidator<TYPE>`:🆕 Requires that the option be convertible to the specified type e.g.  `CLI::TypeValidator<unsigned int>()` would require that the input be convertible to an `unsigned int` regardless of the end conversion.
 
 These Validators can be used by simply passing the name into the `check` or `transform` methods on an option
 
@@ -433,27 +438,27 @@ will produce a check for a number less than or equal to 0.
 
 ##### Transforming Validators
 There are a few built in Validators that let you transform values if used with the `transform` function.  If they also do some checks then they can be used `check` but some may do nothing in that case.
--   `CLI::Bounded(min,max)` will bound values between min and max and values outside of that range are limited to min or max,  it will fail if the value cannot be converted and produce a `ValidationError`
--   The `IsMember` Validator lets you specify a set of predefined options. You can pass any container or copyable pointer (including `std::shared_ptr`) to a container to this Validator; the container just needs to be iterable and have a `::value_type`. The key type should be convertible from a string,  You can use an initializer list directly if you like. If you need to modify the set later, the pointer form lets you do that; the type message and check will correctly refer to the current version of the set.  The container passed in can be a set, vector, or a map like structure. If used in the `transform` method the output value will be the matching key as it could be modified by filters.
+- `CLI::Bounded(min,max)` will bound values between min and max and values outside of that range are limited to min or max,  it will fail if the value cannot be converted and produce a `ValidationError`
+- The `IsMember` Validator lets you specify a set of predefined options. You can pass any container or copyable pointer (including `std::shared_ptr`) to a container to this Validator; the container just needs to be iterable and have a `::value_type`. The key type should be convertible from a string,  You can use an initializer list directly if you like. If you need to modify the set later, the pointer form lets you do that; the type message and check will correctly refer to the current version of the set.  The container passed in can be a set, vector, or a map like structure. If used in the `transform` method the output value will be the matching key as it could be modified by filters.
 After specifying a set of options, you can also specify "filter" functions of the form `T(T)`, where `T` is the type of the values. The most common choices probably will be `CLI::ignore_case` an `CLI::ignore_underscore`, and `CLI::ignore_space`.  These all work on strings but it is possible to define functions that work on other types.
 Here are some examples
 of `IsMember`:
 
--   `CLI::IsMember({"choice1", "choice2"})`: Select from exact match to choices.
--   `CLI::IsMember({"choice1", "choice2"}, CLI::ignore_case, CLI::ignore_underscore)`: Match things like `Choice_1`, too.
--   `CLI::IsMember(std::set<int>({2,3,4}))`: Most containers and types work; you just need `std::begin`, `std::end`, and `::value_type`.
--   `CLI::IsMember(std::map<std::string, TYPE>({{"one", 1}, {"two", 2}}))`: You can use maps; in `->transform()` these replace the matched value with the matched key.  The value member of the map is not used in `IsMember`, so it can be any type.
--   `auto p = std::make_shared<std::vector<std::string>>(std::initializer_list<std::string>("one", "two")); CLI::IsMember(p)`: You can modify `p` later.
--   The `Transformer` and `CheckedTransformer` Validators transform one value into another. Any container or copyable pointer (including `std::shared_ptr`) to a container that generates pairs of values can be passed to these `Validator's`; the container just needs to be iterable and have a `::value_type` that consists of pairs. The key type should be convertible from a string, and the value type should be convertible to a string  You can use an initializer list directly if you like. If you need to modify the map later, the pointer form lets you do that; the description message will correctly refer to the current version of the map.  `Transformer` does not do any checking so values not in the map are ignored.  `CheckedTransformer` takes an extra step of verifying that the value is either one of the map key values, in which case it is transformed, or one of the expected output values, and if not will generate a `ValidationError`.  A Transformer placed using `check` will not do anything.
+- `CLI::IsMember({"choice1", "choice2"})`: Select from exact match to choices.
+- `CLI::IsMember({"choice1", "choice2"}, CLI::ignore_case, CLI::ignore_underscore)`: Match things like `Choice_1`, too.
+- `CLI::IsMember(std::set<int>({2,3,4}))`: Most containers and types work; you just need `std::begin`, `std::end`, and `::value_type`.
+- `CLI::IsMember(std::map<std::string, TYPE>({{"one", 1}, {"two", 2}}))`: You can use maps; in `->transform()` these replace the matched value with the matched key.  The value member of the map is not used in `IsMember`, so it can be any type.
+- `auto p = std::make_shared<std::vector<std::string>>(std::initializer_list<std::string>("one", "two")); CLI::IsMember(p)`: You can modify `p` later.
+- The `Transformer` and `CheckedTransformer` Validators transform one value into another. Any container or copyable pointer (including `std::shared_ptr`) to a container that generates pairs of values can be passed to these `Validator's`; the container just needs to be iterable and have a `::value_type` that consists of pairs. The key type should be convertible from a string, and the value type should be convertible to a string  You can use an initializer list directly if you like. If you need to modify the map later, the pointer form lets you do that; the description message will correctly refer to the current version of the map.  `Transformer` does not do any checking so values not in the map are ignored.  `CheckedTransformer` takes an extra step of verifying that the value is either one of the map key values, in which case it is transformed, or one of the expected output values, and if not will generate a `ValidationError`.  A Transformer placed using `check` will not do anything.
 After specifying a map of options, you can also specify "filter" just like in `CLI::IsMember`.
 Here are some examples (`Transformer` and `CheckedTransformer` are interchangeable in the examples)
 of `Transformer`:
 
--   `CLI::Transformer({{"key1", "map1"},{"key2","map2"}})`: Select from key values and produce map values.
+- `CLI::Transformer({{"key1", "map1"},{"key2","map2"}})`: Select from key values and produce map values.
 
--   `CLI::Transformer(std::map<std::string,int>({"two",2},{"three",3},{"four",4}}))`: most maplike containers work,  the `::value_type` needs to produce a pair of some kind.
--   `CLI::CheckedTransformer(std::map<std::string, int>({{"one", 1}, {"two", 2}}))`: You can use maps; in `->transform()` these replace the matched key with the value.  `CheckedTransformer` also requires that the value either match one of the keys or match one of known outputs.
--   `auto p = std::make_shared<CLI::TransformPairs<std::string>>(std::initializer_list<std::pair<std::string,std::string>>({"key1", "map1"},{"key2","map2"})); CLI::Transformer(p)`: You can modify `p` later. `TransformPairs<T>` is an alias for `std::vector<std::pair<<std::string,T>>`
+- `CLI::Transformer(std::map<std::string,int>({"two",2},{"three",3},{"four",4}}))`: most maplike containers work,  the `::value_type` needs to produce a pair of some kind.
+- `CLI::CheckedTransformer(std::map<std::string, int>({{"one", 1}, {"two", 2}}))`: You can use maps; in `->transform()` these replace the matched key with the value.  `CheckedTransformer` also requires that the value either match one of the keys or match one of known outputs.
+- `auto p = std::make_shared<CLI::TransformPairs<std::string>>(std::initializer_list<std::pair<std::string,std::string>>({"key1", "map1"},{"key2","map2"})); CLI::Transformer(p)`: You can modify `p` later. `TransformPairs<T>` is an alias for `std::vector<std::pair<<std::string,T>>`
 
 NOTES:  If the container used in `IsMember`, `Transformer`, or `CheckedTransformer` has a `find` function like `std::unordered_map`  or `std::map` then that function is used to do the searching. If it does not have a `find` function a linear search is performed.  If there are filters present, the fast search is performed first, and if that fails a linear search with the filters on the key values is performed.
 
@@ -462,6 +467,7 @@ Validators are copyable and have a few operations that can be performed on them
 The name of a Validator, which is useful for later reference from the `get_validator(name)` method of an `Option` can be set via `.name(validator_name)`
 The operation function of a Validator can be set via
 `.operation(std::function<std::string(std::string &>)`.  The `.active()` function can activate or deactivate a Validator from the operation.  A validator can be set to apply only to a specific element of the output.  For example in a pair option `std::pair<int, std::string>` the first element may need to be a positive integer while the second may need to be a valid file.  The `.application_index(int)` function can specify this.  It is zero based and negative indices apply to all values.
+
 ```cpp
 opt->check(CLI::Validator(CLI::PositiveNumber).application_index(0));
 opt->check(CLI::Validator(CLI::ExistingFile).application_index(1));
@@ -514,19 +520,19 @@ opt->get_validator(index);
 
 Which will return a validator in the index it is applied which isn't necessarily the order in which was defined.  The pointer can be `nullptr` if an invalid index is given.
 Validators have a few functions to query the current values
--   `get_description()`: Will return a description string
--   `get_name()`: Will return the Validator name
--   `get_active()`: Will return the current active state, true if the Validator is active.
--   `get_application_index()`: Will return the current application index.
--   `get_modifying()`: Will return true if the Validator is allowed to modify the input, this can be controlled via the `non_modifying()` method, though it is recommended to let `check` and `transform` option methods manipulate it if needed.
+- `get_description()`: Will return a description string
+- `get_name()`: Will return the Validator name
+- `get_active()`: Will return the current active state, true if the Validator is active.
+- `get_application_index()`: Will return the current application index.
+- `get_modifying()`: Will return true if the Validator is allowed to modify the input, this can be controlled via the `non_modifying()` method, though it is recommended to let `check` and `transform` option methods manipulate it if needed.
 
 #### Getting results
 
 In most cases, the fastest and easiest way is to return the results through a callback or variable specified in one of the `add_*` functions.  But there are situations where this is not possible or desired.  For these cases the results may be obtained through one of the following functions. Please note that these functions will do any type conversions and processing during the call so should not used in performance critical code:
 
--   `results()`: Retrieves a vector of strings with all the results in the order they were given.
--   `results(variable_to_bind_to)`: Gets the results according to the MultiOptionPolicy and converts them just like the `add_option_function` with a variable.
--   `Value=as<type>()`: Returns the result or default value directly as the specified type if possible, can be vector to return all results, and a non-vector to get the result according to the MultiOptionPolicy in place.
+- `results()`: Retrieves a vector of strings with all the results in the order they were given.
+- `results(variable_to_bind_to)`: Gets the results according to the MultiOptionPolicy and converts them just like the `add_option_function` with a variable.
+- `Value=as<type>()`: Returns the result or default value directly as the specified type if possible, can be vector to return all results, and a non-vector to get the result according to the MultiOptionPolicy in place.
 
 ### Subcommands
 
@@ -551,65 +557,66 @@ Nameless subcommands function a similarly to groups in the main `App`. See [Opti
 
 There are several options that are supported on the main app and subcommands and option_groups. These are:
 
--   `.ignore_case()`: Ignore the case of this subcommand. Inherited by added subcommands, so is usually used on the main `App`.
--   `.ignore_underscore()`: Ignore any underscores in the subcommand name. Inherited by added subcommands, so is usually used on the main `App`.
--   `.allow_windows_style_options()`: Allow command line options to be parsed in the form of `/s /long /file:file_name.ext`  This option does not change how options are specified in the `add_option` calls or the ability to process options in the form of `-s --long --file=file_name.ext`.
--   `.fallthrough()`: Allow extra unmatched options and positionals to "fall through" and be matched on a parent option. Subcommands always are allowed to "fall through" as in they will first attempt to match on the current subcommand and if they fail will progressively check parents for matching subcommands.
--   `.configurable()`: Allow the subcommand to be triggered from a configuration file. By default subcommand options in a configuration file do not trigger a subcommand but will just update default values.
--   `.disable()`: Specify that the subcommand is disabled, if given with a bool value it will enable or disable the subcommand or option group.
--   `.disabled_by_default()`: Specify that at the start of parsing the subcommand/option_group should be disabled. This is useful for allowing some Subcommands to trigger others.
--   `.enabled_by_default()`: Specify that at the start of each parse the subcommand/option_group should be enabled.  This is useful for allowing some Subcommands to disable others.
--   `.silent()`: 🆕 Specify that the subcommand is silent meaning that if used it won't show up in the subcommand list.  This allows the use of subcommands as modifiers
--   `.validate_positionals()`: Specify that positionals should pass validation before matching.  Validation is specified through `transform`, `check`, and `each` for an option.  If an argument fails validation it is not an error and matching proceeds to the next available positional or extra arguments.
--   `.excludes(option_or_subcommand)`: If given an option pointer or pointer to another subcommand, these subcommands cannot be given together.  In the case of options, if the option is passed the subcommand cannot be used and will generate an error.
--   `.needs(option_or_subcommand)`: If given an option pointer or pointer to another subcommand, the subcommands will require the given option to have been given before this subcommand is validated which occurs prior to execution of any callback or after parsing is completed.
--   `.require_option()`: Require 1 or more options or option groups be used.
--   `.require_option(N)`: Require `N` options or option groups, if `N>0`, or up to `N` if `N<0`. `N=0` resets to the default to 0 or more.
--   `.require_option(min, max)`: Explicitly set min and max allowed options or option groups. Setting `max` to 0 implies unlimited options.
--   `.require_subcommand()`: Require 1 or more subcommands.
--   `.require_subcommand(N)`: Require `N` subcommands if `N>0`, or up to `N` if `N<0`. `N=0` resets to the default to 0 or more.
--   `.require_subcommand(min, max)`: Explicitly set min and max allowed subcommands. Setting `max` to 0 is unlimited.
--   `.add_subcommand(name="", description="")`: Add a subcommand, returns a pointer to the internally stored subcommand.
--   `.add_subcommand(shared_ptr<App>)`: Add a subcommand by shared_ptr, returns a pointer to the internally stored subcommand.
--   `.remove_subcommand(App)`: Remove a subcommand from the app or subcommand.
--   `.got_subcommand(App_or_name)`: Check to see if a subcommand was received on the command line.
--   `.get_subcommands(filter)`: The list of subcommands that match a particular filter function.
--   `.add_option_group(name="", description="")`: Add an [option group](#option-groups) to an App,  an option group is specialized subcommand intended for containing groups of options or other groups for controlling how options interact.
--   `.get_parent()`: Get the parent App or `nullptr` if called on master App.
--   `.get_option(name)`: Get an option pointer by option name will throw if the specified option is not available,  nameless subcommands are also searched
--   `.get_option_no_throw(name)`: Get an option pointer by option name. This function will return a `nullptr` instead of throwing if the option is not available.
--   `.get_options(filter)`: Get the list of all defined option pointers (useful for processing the app for custom output formats).
--   `.parse_order()`: Get the list of option pointers in the order they were parsed (including duplicates).
--   `.formatter(fmt)`: Set a formatter, with signature `std::string(const App*, std::string, AppFormatMode)`. See Formatting for more details.
--   `.description(str)`: Set/change the description.
--   `.get_description()`: Access the description.
--   `.alias(str)`: set an alias for the subcommand, this allows subcommands to be called by more than one name.
--   `.parsed()`: True if this subcommand was given on the command line.
--   `.count()`: Returns the number of times the subcommand was called.
--   `.count(option_name)`: Returns the number of times a particular option was called.
--   `.count_all()`: Returns the total number of arguments a particular subcommand processed, on the master App it returns the total number of processed commands.
--   `.name(name)`: Add or change the name.
--   `.callback(void() function)`: Set the callback for an app. Either sets the `pre_parse_callback` or the `final_callback` depending on the value of `immediate_callback`. See [Subcommand callbacks](#callbacks) for some additional details.
--   `.parse_complete_callback(void() function)`: Set the callback that runs at the completion of parsing. For subcommands this is executed at the completion of the single subcommand and can be executed multiple times. See [Subcommand callbacks](#callbacks) for some additional details.
--   `.final_callback(void() function)`: Set the callback that runs at the end of all processing. This is the last thing that is executed before returning. See [Subcommand callbacks](#callbacks) for some additional details.
--   `.immediate_callback()`: Specifies whether the callback for a subcommand should be run as a `parse_complete_callback`(true) or `final_callback`(false). When used on the main app it will execute the main app callback prior to the callbacks for a subcommand if they do not also have the `immediate_callback` flag set. It is preferable to use the `parse_complete_callback` or `final_callback` directly instead of the `callback` and `immediate_callback` if one wishes to control the ordering and timing of callback.  Though `immediate_callback` can be used to swap them if that is needed.
--   `.pre_parse_callback(void(std::size_t) function)`: Set a callback that executes after the first argument of an application is processed.  See [Subcommand callbacks](#callbacks) for some additional details.
--   `.allow_extras()`: Do not throw an error if extra arguments are left over.
--   `.positionals_at_end()`: Specify that positional arguments occur as the last arguments and throw an error if an unexpected positional is encountered.
--   `.prefix_command()`: Like `allow_extras`, but stop immediately on the first unrecognized item. It is ideal for allowing your app or subcommand to be a "prefix" to calling another app.
--   `.footer(message)`: Set text to appear at the bottom of the help string.
--   `.footer(std::string())`: Set a callback to generate a string that will appear at the end of the help string.
--   `.set_help_flag(name, message)`: Set the help flag name and message, returns a pointer to the created option.
--   `.set_version_flag(name, versionString or callback, help_message)`: Set the version flag name and version string or callback and optional help message, returns a pointer to the created option.
--   `.set_help_all_flag(name, message)`: Set the help all flag name and message, returns a pointer to the created option. Expands subcommands.
--   `.failure_message(func)`: Set the failure message function. Two provided: `CLI::FailureMessage::help` and `CLI::FailureMessage::simple` (the default).
--   `.group(name)`: Set a group name, defaults to `"Subcommands"`. Setting `""` will be hide the subcommand.
--   `[option_name]`: retrieve a const pointer to an option given by `option_name` for Example `app["--flag1"]` will get a pointer to the option for the "--flag1" value,  `app["--flag1"]->as<bool>()` will get the results of the command line for a flag. The operation will throw an exception if the option name is not valid.
+- `.ignore_case()`: Ignore the case of this subcommand. Inherited by added subcommands, so is usually used on the main `App`.
+- `.ignore_underscore()`: Ignore any underscores in the subcommand name. Inherited by added subcommands, so is usually used on the main `App`.
+- `.allow_windows_style_options()`: Allow command line options to be parsed in the form of `/s /long /file:file_name.ext`  This option does not change how options are specified in the `add_option` calls or the ability to process options in the form of `-s --long --file=file_name.ext`.
+- `.fallthrough()`: Allow extra unmatched options and positionals to "fall through" and be matched on a parent option. Subcommands always are allowed to "fall through" as in they will first attempt to match on the current subcommand and if they fail will progressively check parents for matching subcommands.
+- `.configurable()`: Allow the subcommand to be triggered from a configuration file. By default subcommand options in a configuration file do not trigger a subcommand but will just update default values.
+- `.disable()`: Specify that the subcommand is disabled, if given with a bool value it will enable or disable the subcommand or option group.
+- `.disabled_by_default()`: Specify that at the start of parsing the subcommand/option_group should be disabled. This is useful for allowing some Subcommands to trigger others.
+- `.enabled_by_default()`: Specify that at the start of each parse the subcommand/option_group should be enabled.  This is useful for allowing some Subcommands to disable others.
+- `.silent()`: 🆕 Specify that the subcommand is silent meaning that if used it won't show up in the subcommand list.  This allows the use of subcommands as modifiers
+- `.validate_positionals()`: Specify that positionals should pass validation before matching.  Validation is specified through `transform`, `check`, and `each` for an option.  If an argument fails validation it is not an error and matching proceeds to the next available positional or extra arguments.
+- `.excludes(option_or_subcommand)`: If given an option pointer or pointer to another subcommand, these subcommands cannot be given together.  In the case of options, if the option is passed the subcommand cannot be used and will generate an error.
+- `.needs(option_or_subcommand)`: If given an option pointer or pointer to another subcommand, the subcommands will require the given option to have been given before this subcommand is validated which occurs prior to execution of any callback or after parsing is completed.
+- `.require_option()`: Require 1 or more options or option groups be used.
+- `.require_option(N)`: Require `N` options or option groups, if `N>0`, or up to `N` if `N<0`. `N=0` resets to the default to 0 or more.
+- `.require_option(min, max)`: Explicitly set min and max allowed options or option groups. Setting `max` to 0 implies unlimited options.
+- `.require_subcommand()`: Require 1 or more subcommands.
+- `.require_subcommand(N)`: Require `N` subcommands if `N>0`, or up to `N` if `N<0`. `N=0` resets to the default to 0 or more.
+- `.require_subcommand(min, max)`: Explicitly set min and max allowed subcommands. Setting `max` to 0 is unlimited.
+- `.add_subcommand(name="", description="")`: Add a subcommand, returns a pointer to the internally stored subcommand.
+- `.add_subcommand(shared_ptr<App>)`: Add a subcommand by shared_ptr, returns a pointer to the internally stored subcommand.
+- `.remove_subcommand(App)`: Remove a subcommand from the app or subcommand.
+- `.got_subcommand(App_or_name)`: Check to see if a subcommand was received on the command line.
+- `.get_subcommands(filter)`: The list of subcommands that match a particular filter function.
+- `.add_option_group(name="", description="")`: Add an [option group](#option-groups) to an App,  an option group is specialized subcommand intended for containing groups of options or other groups for controlling how options interact.
+- `.get_parent()`: Get the parent App or `nullptr` if called on master App.
+- `.get_option(name)`: Get an option pointer by option name will throw if the specified option is not available,  nameless subcommands are also searched
+- `.get_option_no_throw(name)`: Get an option pointer by option name. This function will return a `nullptr` instead of throwing if the option is not available.
+- `.get_options(filter)`: Get the list of all defined option pointers (useful for processing the app for custom output formats).
+- `.parse_order()`: Get the list of option pointers in the order they were parsed (including duplicates).
+- `.formatter(fmt)`: Set a formatter, with signature `std::string(const App*, std::string, AppFormatMode)`. See Formatting for more details.
+- `.description(str)`: Set/change the description.
+- `.get_description()`: Access the description.
+- `.alias(str)`: set an alias for the subcommand, this allows subcommands to be called by more than one name.
+- `.parsed()`: True if this subcommand was given on the command line.
+- `.count()`: Returns the number of times the subcommand was called.
+- `.count(option_name)`: Returns the number of times a particular option was called.
+- `.count_all()`: Returns the total number of arguments a particular subcommand processed, on the master App it returns the total number of processed commands.
+- `.name(name)`: Add or change the name.
+- `.callback(void() function)`: Set the callback for an app. Either sets the `pre_parse_callback` or the `final_callback` depending on the value of `immediate_callback`. See [Subcommand callbacks](#callbacks) for some additional details.
+- `.parse_complete_callback(void() function)`: Set the callback that runs at the completion of parsing. For subcommands this is executed at the completion of the single subcommand and can be executed multiple times. See [Subcommand callbacks](#callbacks) for some additional details.
+- `.final_callback(void() function)`: Set the callback that runs at the end of all processing. This is the last thing that is executed before returning. See [Subcommand callbacks](#callbacks) for some additional details.
+- `.immediate_callback()`: Specifies whether the callback for a subcommand should be run as a `parse_complete_callback`(true) or `final_callback`(false). When used on the main app it will execute the main app callback prior to the callbacks for a subcommand if they do not also have the `immediate_callback` flag set. It is preferable to use the `parse_complete_callback` or `final_callback` directly instead of the `callback` and `immediate_callback` if one wishes to control the ordering and timing of callback.  Though `immediate_callback` can be used to swap them if that is needed.
+- `.pre_parse_callback(void(std::size_t) function)`: Set a callback that executes after the first argument of an application is processed.  See [Subcommand callbacks](#callbacks) for some additional details.
+- `.allow_extras()`: Do not throw an error if extra arguments are left over.
+- `.positionals_at_end()`: Specify that positional arguments occur as the last arguments and throw an error if an unexpected positional is encountered.
+- `.prefix_command()`: Like `allow_extras`, but stop immediately on the first unrecognized item. It is ideal for allowing your app or subcommand to be a "prefix" to calling another app.
+- `.footer(message)`: Set text to appear at the bottom of the help string.
+- `.footer(std::string())`: Set a callback to generate a string that will appear at the end of the help string.
+- `.set_help_flag(name, message)`: Set the help flag name and message, returns a pointer to the created option.
+- `.set_version_flag(name, versionString or callback, help_message)`: Set the version flag name and version string or callback and optional help message, returns a pointer to the created option.
+- `.set_help_all_flag(name, message)`: Set the help all flag name and message, returns a pointer to the created option. Expands subcommands.
+- `.failure_message(func)`: Set the failure message function. Two provided: `CLI::FailureMessage::help` and `CLI::FailureMessage::simple` (the default).
+- `.group(name)`: Set a group name, defaults to `"Subcommands"`. Setting `""` will be hide the subcommand.
+- `[option_name]`: retrieve a const pointer to an option given by `option_name` for Example `app["--flag1"]` will get a pointer to the option for the "--flag1" value,  `app["--flag1"]->as<bool>()` will get the results of the command line for a flag. The operation will throw an exception if the option name is not valid.
 
 > Note: if you have a fixed number of required positional options, that will match before subcommand names. `{}` is an empty filter function, and any positional argument will match before repeated subcommand names.
 
 
 #### Callbacks
+
 A subcommand has three optional callbacks that are executed at different stages of processing.  The `preparse_callback` is executed once after the first argument of a subcommand or application is processed and gives an argument for the number of remaining arguments to process.  For the main app the first argument is considered the program name,  for subcommands the first argument is the subcommand name.  For Option groups and nameless subcommands the first argument is after the first argument or subcommand is processed from that group.
 The second callback is executed after parsing.  This is known as the `parse_complete_callback`. For subcommands this is executed immediately after parsing and can be executed multiple times if a subcommand is called multiple times.    On the main app this callback is executed after all the `parse_complete_callback`s for the subcommands are executed but prior to any `final_callback` calls in the subcommand or option groups. If the main app or subcommand has a config file, no data from the config file will be reflected in `parse_complete_callback` on named subcommands.  For `option_group`s the `parse_complete_callback` is executed prior to the `parse_complete_callback` on the main app but after the `config_file` is loaded (if specified).  The `final_callback` is executed after all processing is complete.  After the `parse_complete_callback` is executed on the main app, the used subcommand `final_callback` are executed followed by the "final callback" for option groups.  The last thing to execute is the `final_callback` for the `main_app`.
 For example say an application was set up like
@@ -627,20 +634,21 @@ app.preparse_callback( pa);
 
 Then the command line is given as
 
-```
+```bash
 program --opt1 opt1_val  sub1 --sub1opt --sub1optb val sub2 --sub2opt sub1 --sub1opt2 sub2 --sub2opt2 val
 ```
 
--   pa will be called prior to parsing any values with an argument of 13.
--   pc1 will be called immediately after processing the sub1 command with a value of 10.
--   c1 will be called when the `sub2` command is encountered.
--   pc2 will be called with value of 6 after the sub2 command is encountered.
--   c1 will be called again after the second sub2 command is encountered.
--   ac1 will be called after processing of all arguments
--   c2 will be called once after processing all arguments.
--   ac2 will be called last after completing  all lower level callbacks have been executed.
+- `pa` will be called prior to parsing any values with an argument of 13.
+- `pc1` will be called immediately after processing the `sub1` command with a value of 10.
+- `c1` will be called when the `sub2` command is encountered.
+- `pc2` will be called with value of 6 after the `sub2` command is encountered.
+- `c1` will be called again after the second `sub2` command is encountered.
+- `ac1` will be called after processing of all arguments
+- `c2` will be called once after processing all arguments.
+- `ac2` will be called last after completing  all lower level callbacks have been executed.
 
 A subcommand is considered terminated when one of the following conditions are met.
+
 1. There are no more arguments to process
 2. Another subcommand is encountered that would not fit in an optional slot of the subcommand
 3. The `positional_mark` (`--`) is encountered and there are no available positional slots in the subcommand.
diff --git a/book/README.md b/book/README.md
index 4d69b904..ee69437f 100644
--- a/book/README.md
+++ b/book/README.md
@@ -1,8 +1,8 @@
 # CLI11: An introduction
 
-This gitbook is designed to provide an introduction to using the CLI11 library to write your own command line programs. The library is designed to be clean, intuitive, but powerful. There are no requirements beyond C++11 support (and even `<regex>` support not required). It works on Mac, Linux, and Windows, and has 100% test coverage on all three systems. You can simply drop in a single header file (`CLI11.hpp` available in [releases]) to use CLI11 in your own application. Other ways to integrate it into a build system are listed in the [README].
+This gitbook is designed to provide an introduction to using the CLI11 library to write your own command line programs. The library is designed to be clean, intuitive, but powerful. There are no requirements beyond C++11 support (and even `<regex>` support not required). It works on Mac, Linux, and Windows, and has 100% test coverage on all three systems. You can simply drop in a single header file (`CLI11.hpp` available in [releases]) to use CLI11 in your own application. Other ways to integrate it into a build system are listed in the [README][].
 
-The library was inspired the Python libraries [Plumbum] and [Click], and incorporates many of their user friendly features. The library is extensively documented, with a [friendly introduction][README], this tutorial book, and more technical [API docs].
+The library was inspired the Python libraries [Plumbum][] and [Click][], and incorporates many of their user friendly features. The library is extensively documented, with a [friendly introduction][README], this tutorial book, and more technical [API docs][].
 
 > Feel free to contribute to [this documentation here][CLI11Tutorial] if something can be improved!
 
@@ -49,9 +49,9 @@ You can use any valid type; the above example could have used a `boost::file_sys
 
 You can use subcommands, as well. Subcommands support callback lambda functions when parsed, or they can be checked later. You can infinitely nest subcommands, and each is a full `App` instance, supporting everything listed above.
 
-Reading/producing `.ini` files for configuration is also supported, as is using environment variables as input. The base `App` can be subclassed and customized for use in a toolkit (like [GooFit]). All the standard shell idioms, like `--`, work as well.
+Reading/producing `.ini` files for configuration is also supported, as is using environment variables as input. The base `App` can be subclassed and customized for use in a toolkit (like [GooFit][]). All the standard shell idioms, like `--`, work as well.
 
-CLI11 was developed at the [University of Cincinnati] in support of the [GooFit] library under [NSF Award 1414736][NSF 1414736]. It was featured in a [DIANA/HEP] meeting at CERN. Please give it a try! Feedback is always welcome.
+CLI11 was developed at the [University of Cincinnati] in support of the [GooFit][] library under [NSF Award 1414736][NSF 1414736]. It was featured in a [DIANA/HEP] meeting at CERN. Please give it a try! Feedback is always welcome.
 
 [GooFit]: https://github.com/GooFit/GooFit
 [DIANA/HEP]: http://diana-hep.org
diff --git a/book/chapters/config.md b/book/chapters/config.md
index 219c3d9d..f2db1cf5 100644
--- a/book/chapters/config.md
+++ b/book/chapters/config.md
@@ -176,6 +176,6 @@ For custom configuration files this behavior can be triggered by specifying the
 The config file input works with any form of the option given:  Long, short, positional, or the environment variable name.  When generating a config file it will create a name in following priority.
 
 1.   First long name
-1.   Positional name
-1.   First short name
-1.   Environment name
+2.   Positional name
+3.   First short name
+4.   Environment name
diff --git a/book/chapters/flags.md b/book/chapters/flags.md
index d4f88fb6..76c47da7 100644
--- a/book/chapters/flags.md
+++ b/book/chapters/flags.md
@@ -123,4 +123,4 @@ Flag plain: 1
 ```
 
 
-[^1] It will not inherit this from the parent defaults, since this is often useful even if you don't want all options to allow multiple passed options.
+[^1]: It will not inherit this from the parent defaults, since this is often useful even if you don't want all options to allow multiple passed options.
diff --git a/book/chapters/subcommands.md b/book/chapters/subcommands.md
index 230cca88..9d056e8f 100644
--- a/book/chapters/subcommands.md
+++ b/book/chapters/subcommands.md
@@ -7,7 +7,6 @@ C++ application, though the system git uses to extend the main command by callin
 in separate executables is supported too; that's called "Prefix commands" and is included at the
 end of this chapter.
 
-
 ## The parent App
 
 We'll start by discussing the parent `App`. You've already used it quite a bit, to create
@@ -18,7 +17,6 @@ You can replace the default help print when a `ParseError` is thrown with `app.s
 The default is `CLI:::FailureMessage::simple`, and you can easily define a new one. Just make a (lambda) function that takes an App pointer
 and a reference to an error code (even if you don't use them), and returns a string.
 
-
 ## Adding a subcommand
 
 Subcommands can be added just like an option:
diff --git a/examples/callback_passthrough.cpp b/examples/callback_passthrough.cpp
index 16698aaf..48a24875 100644
--- a/examples/callback_passthrough.cpp
+++ b/examples/callback_passthrough.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/config_app.cpp b/examples/config_app.cpp
index 381c147c..aec9fefd 100644
--- a/examples/config_app.cpp
+++ b/examples/config_app.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/custom_parse.cpp b/examples/custom_parse.cpp
index a14d7bd1..44fc77af 100644
--- a/examples/custom_parse.cpp
+++ b/examples/custom_parse.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/digit_args.cpp b/examples/digit_args.cpp
index cf8f7d33..af0891a4 100644
--- a/examples/digit_args.cpp
+++ b/examples/digit_args.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/enum.cpp b/examples/enum.cpp
index a73e56b3..09b7f043 100644
--- a/examples/enum.cpp
+++ b/examples/enum.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/enum_ostream.cpp b/examples/enum_ostream.cpp
index 13d33502..4e3e6b29 100644
--- a/examples/enum_ostream.cpp
+++ b/examples/enum_ostream.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/formatter.cpp b/examples/formatter.cpp
index 81d6209f..3b2e3dce 100644
--- a/examples/formatter.cpp
+++ b/examples/formatter.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/groups.cpp b/examples/groups.cpp
index 22d62894..c766d6b2 100644
--- a/examples/groups.cpp
+++ b/examples/groups.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/inter_argument_order.cpp b/examples/inter_argument_order.cpp
index deecd057..ebee3977 100644
--- a/examples/inter_argument_order.cpp
+++ b/examples/inter_argument_order.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/json.cpp b/examples/json.cpp
index d5fe35a7..ae2595c0 100644
--- a/examples/json.cpp
+++ b/examples/json.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/modhelp.cpp b/examples/modhelp.cpp
index 706abcae..9c674300 100644
--- a/examples/modhelp.cpp
+++ b/examples/modhelp.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/nested.cpp b/examples/nested.cpp
index 97f34290..dc8323fe 100644
--- a/examples/nested.cpp
+++ b/examples/nested.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/option_groups.cpp b/examples/option_groups.cpp
index 679cb754..acc65740 100644
--- a/examples/option_groups.cpp
+++ b/examples/option_groups.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/positional_arity.cpp b/examples/positional_arity.cpp
index eb6639b0..e9238fc7 100644
--- a/examples/positional_arity.cpp
+++ b/examples/positional_arity.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/positional_validation.cpp b/examples/positional_validation.cpp
index 421de250..afc03fa8 100644
--- a/examples/positional_validation.cpp
+++ b/examples/positional_validation.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/prefix_command.cpp b/examples/prefix_command.cpp
index 8977adcb..2af1a87b 100644
--- a/examples/prefix_command.cpp
+++ b/examples/prefix_command.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/ranges.cpp b/examples/ranges.cpp
index 37032e6e..6b4c1e3b 100644
--- a/examples/ranges.cpp
+++ b/examples/ranges.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/retired.cpp b/examples/retired.cpp
index d658e754..3a18db4a 100644
--- a/examples/retired.cpp
+++ b/examples/retired.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/shapes.cpp b/examples/shapes.cpp
index 880441b8..b318df0e 100644
--- a/examples/shapes.cpp
+++ b/examples/shapes.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/simple.cpp b/examples/simple.cpp
index c1354eaf..0f904420 100644
--- a/examples/simple.cpp
+++ b/examples/simple.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/subcom_help.cpp b/examples/subcom_help.cpp
index d41d4a59..89af131d 100644
--- a/examples/subcom_help.cpp
+++ b/examples/subcom_help.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/subcom_in_files/subcommand_a.cpp b/examples/subcom_in_files/subcommand_a.cpp
index 63474fdc..6b229839 100644
--- a/examples/subcom_in_files/subcommand_a.cpp
+++ b/examples/subcom_in_files/subcommand_a.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/subcom_in_files/subcommand_a.hpp b/examples/subcom_in_files/subcommand_a.hpp
index 2993739e..116160c5 100644
--- a/examples/subcom_in_files/subcommand_a.hpp
+++ b/examples/subcom_in_files/subcommand_a.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/subcom_in_files/subcommand_main.cpp b/examples/subcom_in_files/subcommand_main.cpp
index 76ebe7c0..62b63806 100644
--- a/examples/subcom_in_files/subcommand_main.cpp
+++ b/examples/subcom_in_files/subcommand_main.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/subcom_partitioned.cpp b/examples/subcom_partitioned.cpp
index 20dd3623..df48e2d7 100644
--- a/examples/subcom_partitioned.cpp
+++ b/examples/subcom_partitioned.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/subcommands.cpp b/examples/subcommands.cpp
index 937eaeaf..68f163a7 100644
--- a/examples/subcommands.cpp
+++ b/examples/subcommands.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/examples/validators.cpp b/examples/validators.cpp
index 05ea045c..6ca8d389 100644
--- a/examples/validators.cpp
+++ b/examples/validators.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/App.hpp b/include/CLI/App.hpp
index 9bd7599c..b445e49d 100644
--- a/include/CLI/App.hpp
+++ b/include/CLI/App.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
@@ -1763,7 +1763,7 @@ class App {
         if(name_.empty()) {
             return std::string("[Option Group: ") + get_group() + "]";
         }
-        if(aliases_.empty() || !with_aliases || aliases_.empty()) {
+        if(aliases_.empty() || !with_aliases) {
             return name_;
         }
         std::string dispname = name_;
diff --git a/include/CLI/CLI.hpp b/include/CLI/CLI.hpp
index 98fca548..990ba407 100644
--- a/include/CLI/CLI.hpp
+++ b/include/CLI/CLI.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/Config.hpp b/include/CLI/Config.hpp
index ca173168..654c9f20 100644
--- a/include/CLI/Config.hpp
+++ b/include/CLI/Config.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/ConfigFwd.hpp b/include/CLI/ConfigFwd.hpp
index 2fd255c0..35eed52d 100644
--- a/include/CLI/ConfigFwd.hpp
+++ b/include/CLI/ConfigFwd.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/Error.hpp b/include/CLI/Error.hpp
index e6a83257..de3122bb 100644
--- a/include/CLI/Error.hpp
+++ b/include/CLI/Error.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/Formatter.hpp b/include/CLI/Formatter.hpp
index cb9e92a5..e45aa25d 100644
--- a/include/CLI/Formatter.hpp
+++ b/include/CLI/Formatter.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/FormatterFwd.hpp b/include/CLI/FormatterFwd.hpp
index 6908d464..728926c0 100644
--- a/include/CLI/FormatterFwd.hpp
+++ b/include/CLI/FormatterFwd.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/Macros.hpp b/include/CLI/Macros.hpp
index 7398ed77..f228c918 100644
--- a/include/CLI/Macros.hpp
+++ b/include/CLI/Macros.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/Option.hpp b/include/CLI/Option.hpp
index f09f61f9..11ae2c05 100644
--- a/include/CLI/Option.hpp
+++ b/include/CLI/Option.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/Split.hpp b/include/CLI/Split.hpp
index 36c953de..83ef572c 100644
--- a/include/CLI/Split.hpp
+++ b/include/CLI/Split.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/StringTools.hpp b/include/CLI/StringTools.hpp
index 090445e5..84e21de8 100644
--- a/include/CLI/StringTools.hpp
+++ b/include/CLI/StringTools.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/Timer.hpp b/include/CLI/Timer.hpp
index 69728b7d..429ca026 100644
--- a/include/CLI/Timer.hpp
+++ b/include/CLI/Timer.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/TypeTools.hpp b/include/CLI/TypeTools.hpp
index 1736b13a..2b87ec60 100644
--- a/include/CLI/TypeTools.hpp
+++ b/include/CLI/TypeTools.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/include/CLI/Validators.hpp b/include/CLI/Validators.hpp
index 474350fa..e8458622 100644
--- a/include/CLI/Validators.hpp
+++ b/include/CLI/Validators.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
@@ -1113,7 +1113,6 @@ inline std::pair<std::string, std::string> split_program_name(std::string comman
                     esp = end + 1;
                     if(embeddedQuote) {
                         vals.first = find_and_replace(vals.first, std::string("\\") + keyChar, std::string(1, keyChar));
-                        embeddedQuote = false;
                     }
                 } else {
                     esp = commandline.find_first_of(' ', 1);
diff --git a/include/CLI/Version.hpp b/include/CLI/Version.hpp
index 19174481..d09a79c5 100644
--- a/include/CLI/Version.hpp
+++ b/include/CLI/Version.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/scripts/MakeSingleHeader.py b/scripts/MakeSingleHeader.py
index 78714ffb..42e0ee7a 100755
--- a/scripts/MakeSingleHeader.py
+++ b/scripts/MakeSingleHeader.py
@@ -39,12 +39,20 @@ DIR = os.path.dirname(os.path.abspath(__file__))
 
 class HeaderGroups(dict):
     def __init__(self, tag):
+        """
+        A dictionary that also can read headers given a tag expression.
+
+        TODO: might have gone overboard on this one, could maybe be two functions.
+        """
         self.re_matcher = re.compile(
             tag_str.format(tag=tag), re.MULTILINE | re.DOTALL | re.VERBOSE
         )
         super(HeaderGroups, self).__init__()
 
     def read_header(self, filename):
+        """
+        Read a header file in and add items to the dict, based on the item's action.
+        """
         with open(filename) as f:
             inner = f.read()
 
@@ -67,12 +75,18 @@ class HeaderGroups(dict):
                 raise RuntimeError("Action not understood, must be verbatim or set")
 
     def post_process(self):
+        """
+        Turn sets into multiple line strings.
+        """
         for key in self:
             if isinstance(self[key], set):
                 self[key] = "\n".join(self[key])
 
 
-def MakeHeader(output, main_header, files, tag, namespace, macro=None, version=None):
+def make_header(output, main_header, files, tag, namespace, macro=None, version=None):
+    """
+    Makes a single header given a main header template and a list of files.
+    """
     groups = HeaderGroups(tag)
 
     # Set tag if possible to class variable
@@ -129,7 +143,7 @@ if __name__ == "__main__":
     parser.add_argument("--version", help="Include this version in the generated file")
     args = parser.parse_args()
 
-    MakeHeader(
+    make_header(
         args.output,
         args.main,
         args.files,
diff --git a/tests/AppTest.cpp b/tests/AppTest.cpp
index c4f153c0..d779c6de 100644
--- a/tests/AppTest.cpp
+++ b/tests/AppTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
@@ -1933,7 +1933,6 @@ TEST_CASE_METHOD(TApp, "AllowExtrasArgModify", "[app]") {
     app.allow_extras();
     app.add_option("-f", v2);
     args = {"27", "-f", "45", "-x"};
-    auto cargs = args;
     app.parse(args);
     CHECK(std::vector<std::string>({"45", "-x"}) == args);
 
diff --git a/tests/BoostOptionTypeTest.cpp b/tests/BoostOptionTypeTest.cpp
index 2110bcc6..7ed096cd 100644
--- a/tests/BoostOptionTypeTest.cpp
+++ b/tests/BoostOptionTypeTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/ComplexTypeTest.cpp b/tests/ComplexTypeTest.cpp
index b9a5d4e5..4806c544 100644
--- a/tests/ComplexTypeTest.cpp
+++ b/tests/ComplexTypeTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/ConfigFileTest.cpp b/tests/ConfigFileTest.cpp
index fef62d5d..9c138153 100644
--- a/tests/ConfigFileTest.cpp
+++ b/tests/ConfigFileTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/CreationTest.cpp b/tests/CreationTest.cpp
index 0e6e45d6..47900570 100644
--- a/tests/CreationTest.cpp
+++ b/tests/CreationTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/DeprecatedTest.cpp b/tests/DeprecatedTest.cpp
index a25224ca..f763a89d 100644
--- a/tests/DeprecatedTest.cpp
+++ b/tests/DeprecatedTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/FormatterTest.cpp b/tests/FormatterTest.cpp
index 22da56f0..1516945d 100644
--- a/tests/FormatterTest.cpp
+++ b/tests/FormatterTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/HelpTest.cpp b/tests/HelpTest.cpp
index fbf2b453..276bf916 100644
--- a/tests/HelpTest.cpp
+++ b/tests/HelpTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
@@ -1155,6 +1155,7 @@ TEST_CASE("THelp: ChangingDefaults", "[help]") {
     std::vector<int> x = {1, 2};
     CLI::Option *opt = app.add_option("-q,--quick", x);
     x = {3, 4};
+    CHECK(x[0] == 3);
 
     opt->capture_default_str();
 
@@ -1162,6 +1163,7 @@ TEST_CASE("THelp: ChangingDefaults", "[help]") {
     std::string help = app.help();
 
     CHECK_THAT(help, Contains("INT=[3,4] ..."));
+    CHECK(x[0] == 5);
 }
 
 TEST_CASE("THelp: ChangingDefaultsWithAutoCapture", "[help]") {
@@ -1170,6 +1172,7 @@ TEST_CASE("THelp: ChangingDefaultsWithAutoCapture", "[help]") {
     app.option_defaults()->always_capture_default();
 
     std::vector<int> x = {1, 2};
+    CHECK(x[0] == 1);
     app.add_option("-q,--quick", x);
     x = {3, 4};
 
diff --git a/tests/HelpersTest.cpp b/tests/HelpersTest.cpp
index 0c032fbc..5fc2275c 100644
--- a/tests/HelpersTest.cpp
+++ b/tests/HelpersTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
@@ -997,7 +997,12 @@ TEST_CASE("Types: TypeName", "[helpers]") {
     std::string umapName = CLI::detail::type_name<std::unordered_map<int, std::tuple<std::string, double>>>();
     CHECK(umapName == "[INT,[TEXT,FLOAT]]");
 
+    // On older compilers, this may show up as other/TEXT
     vclass = CLI::detail::classify_object<std::atomic<int>>::value;
+    CHECK((CLI::detail::object_category::wrapper_value == vclass || CLI::detail::object_category::other == vclass));
+
+    std::string atomic_name = CLI::detail::type_name<std::atomic<int>>();
+    CHECK((atomic_name == "INT" || atomic_name == "TEXT"));
 }
 
 TEST_CASE("Types: OverflowSmall", "[helpers]") {
@@ -1128,8 +1133,8 @@ TEST_CASE("Types: LexicalConversionDouble", "[helpers]") {
     CHECK((float)x == Approx((float)9.12));
 
     CLI::results_t bad_input = {"hello"};
-    res = CLI::detail::lexical_conversion<long double, double>(input, x);
-    CHECK(res);
+    res = CLI::detail::lexical_conversion<long double, double>(bad_input, x);
+    CHECK_FALSE(res);
 }
 
 TEST_CASE("Types: LexicalConversionDoubleTuple", "[helpers]") {
diff --git a/tests/NewParseTest.cpp b/tests/NewParseTest.cpp
index 81173e08..30a0c9f4 100644
--- a/tests/NewParseTest.cpp
+++ b/tests/NewParseTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/OptionGroupTest.cpp b/tests/OptionGroupTest.cpp
index b50bff0c..05ef2c19 100644
--- a/tests/OptionGroupTest.cpp
+++ b/tests/OptionGroupTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/OptionTypeTest.cpp b/tests/OptionTypeTest.cpp
index 3204d520..296334e3 100644
--- a/tests/OptionTypeTest.cpp
+++ b/tests/OptionTypeTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/OptionalTest.cpp b/tests/OptionalTest.cpp
index 4d8da020..6b07f01c 100644
--- a/tests/OptionalTest.cpp
+++ b/tests/OptionalTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/SetTest.cpp b/tests/SetTest.cpp
index bd817b75..5d225ff6 100644
--- a/tests/SetTest.cpp
+++ b/tests/SetTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/SimpleTest.cpp b/tests/SimpleTest.cpp
index 92262b5e..3051a46d 100644
--- a/tests/SimpleTest.cpp
+++ b/tests/SimpleTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/StringParseTest.cpp b/tests/StringParseTest.cpp
index 190700ce..a9842481 100644
--- a/tests/StringParseTest.cpp
+++ b/tests/StringParseTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/SubcommandTest.cpp b/tests/SubcommandTest.cpp
index 88a147d2..108f9991 100644
--- a/tests/SubcommandTest.cpp
+++ b/tests/SubcommandTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/TimerTest.cpp b/tests/TimerTest.cpp
index 8c88f478..11e6e121 100644
--- a/tests/TimerTest.cpp
+++ b/tests/TimerTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/TransformTest.cpp b/tests/TransformTest.cpp
index 84ac544a..76a1eff8 100644
--- a/tests/TransformTest.cpp
+++ b/tests/TransformTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/TrueFalseTest.cpp b/tests/TrueFalseTest.cpp
index aa8886c0..c3b556c3 100644
--- a/tests/TrueFalseTest.cpp
+++ b/tests/TrueFalseTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/WindowsTest.cpp b/tests/WindowsTest.cpp
index 84726664..5a75908c 100644
--- a/tests/WindowsTest.cpp
+++ b/tests/WindowsTest.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/app_helper.hpp b/tests/app_helper.hpp
index 0f72adda..91991682 100644
--- a/tests/app_helper.hpp
+++ b/tests/app_helper.hpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/informational.cpp b/tests/informational.cpp
index 92f7dc4c..f0fc70ba 100644
--- a/tests/informational.cpp
+++ b/tests/informational.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/link_test_1.cpp b/tests/link_test_1.cpp
index be910376..447afbf4 100644
--- a/tests/link_test_1.cpp
+++ b/tests/link_test_1.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/link_test_2.cpp b/tests/link_test_2.cpp
index b8544ab4..abce5493 100644
--- a/tests/link_test_2.cpp
+++ b/tests/link_test_2.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/main.cpp b/tests/main.cpp
index f1c2725f..f5fbebd8 100644
--- a/tests/main.cpp
+++ b/tests/main.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //
diff --git a/tests/mesonTest/main.cpp b/tests/mesonTest/main.cpp
index 69813782..64d45eb6 100644
--- a/tests/mesonTest/main.cpp
+++ b/tests/mesonTest/main.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2020, University of Cincinnati, developed by Henry Schreiner
+// Copyright (c) 2017-2021, University of Cincinnati, developed by Henry Schreiner
 // under NSF AWARD 1414736 and by the respective contributors.
 // All rights reserved.
 //