I am creating a completely unique setting for Dungeons & Dragons 5th Edition, and really pouring my heart and soul into it. Under Wizards of the Coast's OGL (Open Gaming License), I am hoping to sell this setting as a supplement book (probably a downloadable PDF through DriveThruRPG).
However, I'm a little bit fuzzy on the differences between the OGL, and the SRD, and what I'm allowed to use vs. what I'm not in the context of a commercial product. Specifically, I was thinking of referencing some non-SRD cleric domains (the only SRD cleric domain, as far as I know, is Life), such as, say, the ones from the Player's Handbook, in the context of locations that are tied to particular Domains. Would that be permissible? I don't know if I'm allowed to use non-SRD domains in a commercial work. I wouldn't be reproducing the actual Domains, in their specific mechanics, just referencing their existence.