anchor.diff:  <%
   # To make changes to this man page:
   #
  -# - For changes to a specific command (appears in the `COMMANDS` section):
  -#   - Edit the top comment in `Library/Homebrew/cmd/<command>.{rb,sh}`.
  -#   - Make sure to use the line prefix `#:` for the comments to be recognized as
  -#     documentation. If in doubt, compare with already documented commands.
  +# - For changes to a command under `COMMANDS` or `DEVELOPER COMMANDS` sections):
  +#   - Find the source file in `Library/Homebrew/[dev-]cmd/<command>.{rb,sh}`.
  +#   - For `.rb` files, edit the `<command>_args` method.
  +#   - For `.sh` files, edit the top comment, being sure to use the line prefix
  +#     `#:` for the comments to be recognized as documentation. If in doubt,
  +#     compare with already documented commands.
  +# - For global options: Edit `Library/Homebrew/cli/parser.rb`.
  +# - For environment variables: Edit `Library/Homebrew/env_config.rb`.
   # - For other changes: Edit this file.
   #
   # When done, regenerate the man page and its HTML version by running `brew man`.
   %>
  -brew(1) -- The Missing Package Manager for macOS
  -================================================
  +brew(1) -- The Missing Package Manager for macOS (or Linux)
  +===========================================================
   
   ## SYNOPSIS
   
  
positive.code: 
  ## ENVIRONMENT
  
  Note that environment variables must have a value set to be detected. For example, run
  `export HOMEBREW_NO_INSECURE_REDIRECT=1` rather than just
  `export HOMEBREW_NO_INSECURE_REDIRECT`.
  
  <%= environment_variables %>
  
negative.code: 
  Homebrew, like `git`(1), supports external commands. These are executable
  scripts that reside somewhere in the `PATH`, named `brew-`<cmdname> or
  `brew-`<cmdname>`.rb`, which can be invoked like `brew` <cmdname>. This allows
  you to create your own commands without modifying Homebrew's internals.
  
  Instructions for creating your own commands can be found in the docs:
  <https://docs.brew.sh/External-Commands>
  