PHR is associated with the USEF, but is not limited to the USA. I believe it was originally started to track non racing throughbreds and tb crosses not associated with warmblood or sporthorse registries, but is now an open/all breed registry. They do record DNA on stallions and mares. They do not inspect or have "standards" they just record info. It is useful for proof of age, pedigree, and ownership of horses that don't fit into regular registries ie AI tb, or cross breds. I have used it, once for a draft/tb cross weanling whose tb sire was reg but not approved anywhere, and once for a pure tb who had known pedigree but was of an age that JC registry was rediculosly expensive and not going to race. I know someone who used it on a non racing tb, again over age for economical JC registration as she needed proof of age and canadian breeding for a show. The fee is reasonable, you get convenient papers, and they maintain DNA records. It is not the "gold standard" of registries but it does help prevent info from being lost when horses change hands or just as time passes (verbal info vs written).