The Pyramid Society has established definitions of such bloodlines which are acceptable for its expressed purpose of promoting and perpetuating Egyptian Arabian bloodlines. These are:

Straight Egyptian Arabian
To qualify as a Straight Egyptian, as defined by The Pyramid Society, a horse must trace in every line of its pedigree to a horse which falls into the following categories:

A. Registered or eligible by pedigree for registration by the Arabian Horse Registry of America; and
B. Traces in every line of its pedigree to horses born in Arabia Deserta; and
C. Traces in every line of its pedigree to a horse which falls within one or more of the following categories of horses:

1. owned or bred by Abbas Pasha I or Ali Pasha Sherif
2. used to create and maintain the Royal Agricultural Society (RAS)/Egyptian Agricultural Organization (EAO) breeding programs, with the exclusion of Registan and Sharkasi and their lineal descendants
3. a horse which was a lineal ancestor of a horse described in (A) or (B) above; and
4. other than those excluded above, who was conceived and born in a private stud program in Egypt and imported directly to the United States and registered by the Arabian Horse Registry of America prior to the extension of the EAO's supervision to private Egyptian st

Al Khamsa, Inc., founded in 1975, is a not-for-profit organization that is devoted to the preservation of the horse of Bedouin Arabia. Al Khamsa, Inc. draws admirers of such horses together through education and research. The horses of interest to Al Khamsa, Inc. meet two criteria: (1) those horses that Al Khamsa, Inc. reasonably assumes to descend entirely from Bedouin Arabian horses that were bred by the nomadic horse-breeding tribes of the deserts of the Arabian Peninsula and (2) have breeding descendants in North America.

Horses that meet the above criteria constitute The Al Khamsa, Inc. Roster . Al Khamsa, Inc. has traditionally called the Roster horses "Al Khamsa Arabians.” The term "Al Khamsa Arabian,” as used by Al Khamsa, Inc., is not synonymous with or interchangeable with any term or designation used by any other organization or entity.

The Roster includes breeding horses in North America and their ancestors. It begins with Foundation Horses (175 as of 2004) and lists all descendants from them with bloodlines still breeding in North America. Foundation Horses are the earliest horses that meet the criteria.

The Roster changes constantly. Such factors as exports, imports, geldings, deaths, eligible progeny and registration authorities affect The Al Khamsa, Inc. Roster .