7. Using POD for Documentation
POD is short for "Plain Old Documentation", and is a lightweight markup language, which is the de-facto standard for writing documentation for Perl programs, Perl modules and Perl itself.
In the context of Perl modules, POD is primarily used to give API (Application Programmers' Interface) documentation. In the context of Perl programs, POD is primarily used to document the usage of the program and the command line flags it accepts. POD is also used to document the perl core (so-called perldocs).