See "man 7 man" for details.

Thanks. (Sadly, Mac OS X seems to omit this manpage, but I found it online.)

The sections headings they refer to as "traditional" are NAME, SYNOPSIS, DESCRIPTION, OPTIONS, FILES, SEE ALSO, DIAGNOSTICS, BUGS, and AUTHOR. (The only required one is NAME, which must follow the "name - brief description" format.)

A quick comparison shows that most of those headings are among the most common in module POD documentation.