The Designation of Open Game Content in the legal appendix of this book indicates that the entirety of the text contained within the volume is open game content, with the exception of a couple of names and descriptions. (Never mind that some of these terms -- such as daoine sidhe -- may already be in the public domain by virtue of their appearance in the mythology of the British Isles)
The Designation of Product Identity is then used to 'cripple' the OGC, stating that the following items are not OGC, but rather Product Identity as defined in Section 1(e) of the OGL:
"any specific characters, monsters, creatures and places; original names of places, artifacts, characters, races, countries, creatures, geographic locations, gods, historic events, magic items, organizations, spells, feats, and abilities; any and all stories, storylines, plots, thematic elements, and dialogue; all artwork, symbols, designs, depictions, illustrations, maps and cartography, likenesses, poses, symbols or graphic elements".