Those who are accepted can participate in club events, or be used as approved breeding stock.
Those that are accepted should have in their description:
Approved DHH by the ERDHHR and the first or second premium depending on what they received. Stallions should also have whether or not they are approved, or unapproved as a stud. (those who have no offspring yet do not need anything)
What if my horse is not accepted?
If it is at the 6 year old keuring, you may try again at the 10year old + keuring. If not then, the horse is not acceptable as breeding stock.
What if my stud is disapproved as a DHH stud? Do I have to geld him?
He may not be used as a DHH stallion, but that does not mean he has to be gelded. It's your choice.