Hmmm. Well, I know that if I gave someone a gift het and they asked for paperwork, I'd be a little disappointed. I realize not everyone is trustworthy, but paperwork--as many here have mentioned--is only as honest as the person who creates it. Yes, it's proof that the seller/giver guaranteed a het, but it will take several years (maturing time and two or three clutches) before the receiver can say within a reasonable doubt that the het isn't really a het. How many people would complain to the original seller/giver five years down the road that it isn't a het? How many sellers/givers would refund or replace the animal after that long a time?

Eh, I'd just say graciously accept the gift and treat it as a possible het until it's proven (or not, as the case may be). Gift horse in the mouth and all....