3.9.5 The help string of procedures

The help string of a procedure should have the following format:

USAGE:    <proc_name>(<parameters>);   <explanation of parameters>
[CREATE:  <description of created objects which are not returned>]
RETURN:   <description of the purpose and return value>
[NOTE:    <particular assumptions or limitations, details>]
[SEE ALSO: <comma-separated names of related procedures/cross references>]
[KEYWORDS: <semicolon-separated phrases of index keys>]
EXAMPLE:  example <proc_name>; shows an example

Further arbitrary items (like THEORY:, or BACKGROUND:) are recognized, as well, but should be used diligently.

Remember that help strings are formatted as explained in Typesetting of help strings. In particular, descriptions may contain the texinfo markup elements @*, @math{..}, @code{..}, @example, @format, @texinfo to better control their typesetting. See msum, mdouble, mtripple for examples.