Adding comments to the message source file
You can include a comment anywhere in a message source file except within message text. Leave at least one space or tab (blank) after the $ (dollar sign).
The following is an example of a comment:
$ This is a comment.
Comments do not appear in the message catalog generated from the message source file.
Comments can help developers in the process of maintaining message
source files, translators in the process of translation, and writers
in the process of editing and documenting messages. Use comments to
identify what variables, such as %s, %c,
and %d, represent. For example, create a note
that states whether the variable refers to a user, file, directory,
or flag. Comments also should be used to identify obsolete messages.
For clarity, you should place a comment line directly beneath the message to which it refers, rather than at the bottom of the message catalog. Global comments for an entire set can be placed directly below the $set directive.