D&D 5E Which parts of Doctors & Daleks are OGC?

[Reynard]

Publishing something that puts them in the sights if the BBC's giant evil lawyers.

I don't know why they would want that. Sounds expensive. Besides, the only way you could publish such a thing would be to impinge on the trademarks, and that would just be foolish. "Compatible with the 5E Dr. Who RPG" on the cover might do it, though.