I think I need to clarify this all.
We have a breed called deutsches Sportpferd - that is a fairly new registry and was created by combining the registries Berlin-Brandenburg, Sachsen-Anhalt, Sachsen und Thüringen. The are using the brand that was used in eastern Germany (a snake with an arrow from right to left). That is the registry of Poetin. Deutsches Sportpferd would translate to “german sporthorse”.
Than someone mentioned ZfdP that is actually Zuchtverband für deutsche Pferde this transalated to Breeding registry of german horses. No warmblood in there as they have in their registry a lot o horses inclusing ponies, also e…g. and an artificial breed called barock pinto.
My guees:
Naturally if someone has a warmblood from Germany or of a german registry he/she may say “I have a German Warmblood” if he she is sure people have no clue what a westfalian or hanoverian etc. may be.
A registry that would translate back from German Warmblood does not exist. But there are some sort of thoughts to cooperate and than act with the Name German warmblood - but I doubt that this will not happen as I guess all the registry heads will not want to leave their chairs…