What most naturally follows?

How to register a horse
Identify the breed of your horse.
If you plan to show or compete with your horse, you likely know what breed they are. A horse trainer or veterinarian that works on different types of horses can help you identify the likely breed if you're unsure.
Visit different breed association websites to read about the characteristics of different breeds. These websites will contain guidelines, specifications and rules about registering a horse for that specific breed.