File: m4.info,  Node: Names,  Next: Quoted strings,  Up: Syntax

3.1 Macro names
===============

A name is any sequence of letters, digits, and the character ‘_’
(underscore), where the first character is not a digit.  ‘m4’ will use
the longest such sequence found in the input.  If a name has a macro
definition, it will be subject to macro expansion (*note Macros::).
Names are case-sensitive.

   Examples of legal names are: ‘foo’, ‘_tmp’, and ‘name01’.