A substantive title, in the United Kingdom, is a title of nobility which is owned in its own right, as opposed to titles shared among cadets, borne as a courtesy title by a peer's relatives, or acquired through marriage.[1]
The Almanach de Gotha treated titles used by dynasties of abolished monarchies:[2] the head of the house bearing a traditional title of the dynasty in lieu of or after the given name.
In accordance with a tradition dating back to the reign of Napoleon I, titles in pretence were treated by the Almanach de Gotha as if still borne by members of reigning dynasties.[2]
. Secrets of the Gotha. Ghislain de Diesbach . 1967. Chapman & Hall. UK, pp. 23-24, 29, 37.