use POD or die $!;

##</code><code>##

# function: foo
# input   : bar baz
# output  : qux
# precond : bar and baz are defined
# postcond: qux is defined
sub foo {
}

##</code><code>##

=for comment
 function: foo
 input   : bar baz
 output  : qux
 precond : bar and baz are defined
 postcond: qux is defined
=cut
sub foo {
}