As others here have said, most Perl certifications - or, for that matter, most employer tests for programming ability - are inane. At one point, when $COMPANY wanted to hire me (I wasn't all that interested, but figured I'd see what they had to offer), they asked one of their people to vet my Perl knowledge. The questions he asked me mainly demonstrated his ignorance of Perl as well as his ignorance of the interviewing process. One sequence that I really treasure was when he asked me what the variable types in Perl were. When I read off the mantra of $, @, and %, and possibly & (and even cited the relevant part of "perldoc perldata" from memory), he hemmed and hawed and insisted that I missed one - then insisted that filehandles (not even globs, but specifically filehandles) were a "variable type that was introduced in Perl 4" (!!!) The interview went nowhere after that point, of course - their "programmer" decided that I didn't know Perl based on this "evidence".
It's worth noting that $COMPANY is one of the largest, richest companies in the world; I'm certain that they have plenty of Perl and interviewing expertise on tap - but their clueless behavior arbitrarily reduced their pool of available talent. Dumb.
Human history becomes more and more a race between education and catastrophe. -- HG Wells