This is the idea with teh Standard of Perfection. Insofar as cpoultry reproduce at such a quick and copious rate and often have a short and/or unpredictible life-span, registries were not seen as possible. The Standard becomes their registry. In theory, a specimen is held up to the Standard and it is. or is not, in accord with whether or not it meets that standard. One of the obvious weaknesses with this system is that birds with a borken lineage can be phenotypically a breed that they genotypically are not. On the other hand, it's hard enough to make this happen, as well as time consuming enough, as to reduce the magnitude of the concern.
Thus, though, when one says Standard-bred Dorking it is the same as saying Registered Holstein, which is why it is taken so seriously.