that brings up a good question though. How would any of us really know someone is certified any time we ask for their papers?
As far as my own employees, its easy I test them, and make out the certs. But we have some outside companies (small ones) who sometimes do a misc. job for us but are still required to be certified. If someone like them used a service like that, I wouldn't know. All I ever receive is a copy of a cert and I make sure the guy who's standing their matches the name on the paper. How many times have we gotten certs from 10 years ago and then if your lucky, a continuity log also, I'd still never know if it was done by some fly by night service unless they told me or I re-tested him myself.
Chris