What is the maximum number of characters that can be used for a race horse's name?

Since 1894, the Jockey Club has been charged with maintaining The American Stud Book, a registry of all Thoroughbreds foaled in the United States, Canada, and Puerto Rico, as well as Thoroughbreds imported into those countries. North American breeders register approximately 37,000 Thoroughbreds each year and the Jockey Club has an online database of more than 430,000 names in active use, all of which must first be approved by the organization's censors.

The first rule of naming a horse is that a name may consist of no more than 18 letters, and spaces and punctuation marks count as letters. Eighteencharacters is acceptable (and is, in fact, a registered horse name) but Eighteen Characters is not. Other ineligible submissions include names consisting entirely of initials; names clearly having commercial, artistic, or creative significance; names that are suggestive or have a vulgar or obscene meaning; names considered in poor taste or names that may be offensive to religious, political or ethnic groups; and names of living persons unless written permission to use their name is on file with The Jockey Club.