Master of the Royal Secret and Sublime Prince of the Royal Secret name the same thirty second degree under the Scottish Rite's two American governing bodies, the Southern and Northern Masonic Jurisdictions respectively, a naming difference documented openly in general reference works on the Rite's organizational history rather than treated as obscure or specialist knowledge.
Published Scottish Rite literature describes the degree as the practical summit of the Rite's petitioned sequence, closing the Consistory body and completing all twenty nine numbered degrees, four through thirty two, that a member works through by petition. This structural fact, that nothing above it is petitioned at all, is itself among the most consistently published details about the degree.
General accounts of the Scottish Rite's American organizational split into Northern and Southern Jurisdictions, a nineteenth century division that produced these parallel titles for the thirty second degree, situate Master of the Royal Secret within that broader, publicly documented history of how the Rite came to be governed by two separate bodies in the United States.
That two governing bodies confer what is, in substance, the same culminating petitioned degree under two different names is itself the kind of structural detail general Scottish Rite reference works present prominently, since it explains a naming inconsistency a reader might otherwise take for two distinct degrees.