I think a large part of the problem here is the breadth of applicability of perl - you can be an expert perl programmer, without even touching (let alone learning to expert level) the use of substantial parts of the language.

For example, I'd rate myself as an excellent perl programmer, but I've never used formats. Nor have I ever used perl on a Windows or Mac platform. I've written threaded applications, but not in perl. I've never written any XS code except for testing purposes.

However, I've been able to gain employment with my perl skills, because I've been able to show that in any area that might be required I know how to acquire the skills I need if I don't already have them.

The point, then, is that anyone hiring perl programmers needs to consider what they need them for, to decide from that what they insist any new programmer must know before starting, and then to devise a means of determining (probably, I guess, by way of a test) whether a candidate knows the prerequisites and can show some ability to learn new things.

Few if any employers need a programmer that is an expert in every aspect of the language and deployment of perl. Any certification that did not take into account your specific needs must, I feel, either certify too few people or too many to be of any help.

Hugo