Current Perl documentation can be found at perldoc.perl.org.
Here is our local, out-dated (pre-5.6) version:
Use embedded POD to discard it:
# program is here
=for nobody This paragraph is commented out
# program continues
=begin comment text
all of this stuff
here will be ignored by everyone
=end comment text
This can't go just anywhere. You have to put a pod directive where the parser is expecting a new statement, not just in the middle of an expression or some other arbitrary yacc grammar production.