14.1.3 Inserting `,' with @comma{}

Ordinarily, a comma `,' is a normal character that can be simply typed in your input where you need it.

However, Texinfo uses the comma as a special character in one uncommon context: some commands, such as @acronym (see section @acronym{acronym[, meaning]}) and @xref (see section Cross References), as well as user-defined macros (see section Defining Macros), can take more than one argument. In these cases, the comma character is used to separate arguments.

Since a comma character would confuse Texinfo's parsing for these commands, you must use the command ‘@comma{}’ instead if you want to pass an actual comma. Here are some examples:

@acronym{ABC, A Bizarre @comma{}}
@xref{Comma,, The @comma{} symbol}
@mymac{One argument@comma{} containing a comma}

Although , can be used nearly anywhere, there is no need for it anywhere except in this unusual case.