USET The United States Equestrian Team (a non-profit organization) holds selection trials for top U.S. horse/rider combinations that have aspirations of competing in the Olympic Games and World Championships. Once riders have been selected by the USET to compete in major international competitions, these riders have the financial support of the USET so that they can pursue their training and competition goals.
USDF The stated goal of the United States Dressage Federation, Inc. is "of promoting and encouraging a high standard of accomplishment in dressage throughout the United States, primarily through educational programs." In addition to educational programs, the USDF offers numerous awards programs, boasts thousands of individual members as well as numerous dressage club members (Group Member Organizations (GMOs)), and produces the monthly magazine "USDF Connection."
USA Equestrian USA Equestrian writes the rules for U.S. dressage competitions. They are also responsible for writing Training through Fifth level tests. USA Equestrian members receive their rule book and magazine, "Horse Show," which keeps members up-to-date on late breaking news and emergency rule changes. You can see their entire rule book on-line.
FEI The Federation Equestre Internationale is the international governing body of equestrian events. The FEI is responsible for writing and administering rules for international competitions and for writing the international level dressage tests (Prix St Georges, Intermediaire I, Intermediaire II, Grand Prix, and Grand Prix Special).