Editing Breed registry (section)

==Open stud book==
In an open stud book, animals may be registered even if their parents or earlier ancestors were not previously registered with that particular entity. Usually an open stud book has strict [[studbook selection]] criteria that require an animal to meet a certain standard of conformation, performance or both. This allows breeders to modify breeds by including individuals who conform to the breed standard but are of outside origin. Some [[horse breed]]s allow [[crossbred]]s who meet specific criteria to be registered. One example is the semi-open stud book of the [[American Quarter Horse]], which still accepts horses of Thoroughbred breeding, particularly via its [[#Appendix registries|appendix registry]]. Among dogs, an example of an open stud book would be the registries maintained by the [[American Kennel Club]] as its Foundation Stock Service. In some cases, an open stud book may eventually become closed once the breed type is deemed to be fully set.

In some agricultural breeds, an otherwise closed registry includes a ''grading up'' route for the incorporation of cross-bred animals. Often such incorporation is limited to females, with the progeny only being accepted as full pedigree animals after several generations of breeding to full-blood males. Such mechanisms may also allow the incorporation of purebred animals descended from unregistered stock or of uncertain parentage.<ref>''British White Cattle Society Constitution, Rules and Byelaws'', [UK] British White Cattle Society, 1998, ("Base Cow Register" and "Grading-up Regulations"). Allows inclusion of inspected cross-bred female cattle after four generations of crossing with registered males, or inspected pure-bred non-pedigree female cattle after three generations.</ref><ref>''Shetland Sheep Society Information Handbook'', [UK] Shetland Sheep Society, 2007, (p20: Rule 3.3, "The Experimental Register"). Allows inclusion of inspected non-pedigree female sheep after three generations of crossing with registered males.</ref>

More controversial open stud books are those where there are few, if any qualifications for animals other than a single trait, such as a "[[color breed]]," particularly when the color is not a true-breeding characteristic. However, some breeds have a standard color or color preference that is one criterion among others used to register animals.

===Appendix registries===
Some open or partly open registries may permit animals who have some but not all qualifications for full registration to nonetheless be entered in a preliminary recording system often called an "appendix" registry. The most notable is that of the [[American Quarter Horse Association]], which allows part-Thoroughbred/part-Quarter Horse foals to be recorded and shown, with full registration allowed after the horse achieves a set performance or merit standard akin to that of a merit registry. Other appendix registries are seen in certain [[color breed]]s of horses, such as the [[Appaloosa]], [[American Paint Horse]], and [[American Cream Draft Horse]], where foals with the proper pedigree for registration but do not meet the color standard for the breed, yet may still carry the necessary genetics in a minimally-expressed form, may be registered and bred to fully registered animals, with ensuing offspring eligible for registration if they meet the breed standard.

===Performance or merit===
Another form of open registry is a registry based on performance or conformation, called in some societies ''Registry on Merit.'' In such registries, an eligible animal that meets certain criteria is eligible to be registered ''on merit,'' regardless of ancestry. In some cases, even unknown or undocumented ancestry may be permitted.

The Registry on Merit or ROM may be tied to percentage of bloodline, conformation, or classification or may be based solely on performance.

In the horse world, many [[warmblood]] breed organizations require a conformation and performance standard for registration, and often allow horses of many different breeds to qualify, though documented pedigrees are usually required. Some breed registries use a form of ROM in which horses at certain shows may be sight classified. For example, at qualifying shows in [[Australia]], winning horses of stock-type breeding receive points for conformation, which are attested to by the judges and recorded in an owner's special book. The points are accumulated to eventually result in a Registry on Merit.

Registry on Merit is prevalent with [[Herding dog|sheepdog]] registries, in particular those of the [[Border Collie]], and some other breeds with a heavy emphasis on [[Working dog|working ability]]. In this type of ROM, the dog's conformation and ancestry generally does not matter.