Maybe I'm misreading the legalese, but am I to believe that all the product I've seen that use the "Pathfinder roleplaying game compatible" stamp all have writen consent for Paizo? Or is that stamp fair game and the open game licence is talking about using their regular logos and stuff? 7. Use of Product Identity: You agree not to Use any Product Identity,
including as an indication as to compatibility, except as expressly
licensed in another, independent Agreement with the owner of each
element of that Product Identity. You agree not to indicate
compatibility or co-adaptability with any Trademark or Registered
Trademark in conjunction with a work containing Open Game Content except
as expressly licensed in another, independent Agreement with the owner
of such Trademark or Registered Trademark. The use of any Product
Identity in Open Game Content does not constitute a challenge to the
ownership of that Product Identity. The owner of any Product Identity
used in Open Game Content shall retain all rights, title and interest in
and to that Product Identity.