Hmmm - after desperately searching for a module in the standard distribution of Perl, I have to admit that I can't come up with an example of bad documentation. I only remember that the documentation for HTML::Parser was really bad, as they documented that one could "use either the version 2 compatible interface" (which was nowhere documented but maybe in the obsolete version of this module that was no more around) or the new (and completely different) version 3 interface, but the documentation completely lacked any example. Maybe that's because the documentation for this module is supposed to be in some book, I don't know.

But nonetheless, I have to admit, Perl module documentation is not bad in general, it was only my perception of the documentation (you seldom notice good documentation :).