	German Warmblood may refer generally to any of the various warmblood horses of Germany, or more specifically to a warmblood registered with the nationwide German Horse Breeding Society (ZfDP). Beneath the umbrella term "German warmblood" are several regional variations on a singular standard; individual German warmblood types are not necessarily considered "breeds", because they have an open stud book and freely exchange genetic material between each other, with other warmblood types, with Anglo-Arabians, and with breeds like the Thoroughbred, Arabian, and Trakehner. (The Trakehner, while a warmblood horse from Germany, has a closed stud book and thus, like the Thoroughbred and Arabian, is considered a "true" breed.)