Let's assume Alice produces a work that lists lore and statistics for beasts, and how to prepare them for adventure meals, and calls it Monster Cookbook, or MC for short. In it, Alice lists a creature on page XX that could be best summarized as a flying orb with a giant mouth with more mouths added on stalks and declares that thing is called a Gourmet.
Now, Alice decides to use the OGL (Open Game License) 1.0a for her Monster Cookbook and declares the the Gourmet is a product identity.
Bob now wants to write an adventure set in a gigantic restaurant. He wants to feature the Gourmet... Normally just writing "Gourmet (Alice: MC, p.XX)" would qualify as fair use (as you reference a fact) but here, we have the OGL providing this:
- 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.
May Bob provide a pointer to Alice book or does he breach the License if he does?