Originally Posted by hellojeffy
I think those need to be witnessed by CGC in person, but I may be wrong. Unverified sigs come back in as Green label (which might bring down value).
Exactly. You can only get the yellow label if CGC witnesses the signature and you submit it to them in person at a convention. That's why the yellows pull in such a premium over Green Labels. Green labels are could be the same exact book but without CGC witnessing the signature they will not give it a yellow label.