http://www.ifpda.org/content/

The International Fine Print Dealers Association (IFPDA) is a non-profit organization of leading art dealers, galleries, and publishers with expertise in the field of fine prints. Members are committed to the highest standards of quality, ethics, and connoisseurship, and to promoting a greater appreciation of fine prints among collectors and the general public.

FAQS: http://www.ifpda.org/content/collecting_prints/faq