Names are limited to a maximum of 18 characters, including spaces and punctuation.

Names cannot match or sound too similar to an active registered name.

Triple Crown winners, Eclipse Award winners, Hall of Fame inductees, and recent Grade 1 winners are restricted.

Sexually suggestive, vulgar, obscene, or offensive names are rejected.

Living or deceased people's names require explicit written permission.

Names with obvious commercial, artistic, or creative significance are prohibited.

Names cannot end in horse-related terms (filly, colt, mare, stud, stallion) or ordinals like 2nd or 3rd.

Names cannot consist entirely of numbers or initials. Numbers above 30 must be spelled out.