International Side Saddle Organization
ISSO's Standards for tack, attire, and equitation. Note these were printed in 1986, and references to AHSA (now USEF) and other specifics may be outdated. Contains useful information on equitation, even if you do not intend to show.
United States Equitation Foundation
See A Discipline's Rulebook By Clicking Its Blue Button
DR120 Dress 7. and DR121 Saddlery and Equipment 10. (Exception: Competitors riding sidesaddle may carry a whip no longer than 47.2 inches (120 cm), including lash, in USEF/USDF Championships.) Para-Equestrians are permitted to use only one stirrup when riding aside.
Side saddles are prohibited in Saddle Seat equitation. Hunter and Western equitation riders "may ride side saddle in Adult Equitation classes but not in classes restricted to Juniors."
" EV114 Dress 3. WHIPS. "riders competing sidesaddle may carry a whip in the dressage test at all competitions, including championships."
Hunter (updated 2/19/17)
Extensive rules covering attire, tack, and conduct and specifications of classes. Of particular interest are HU129 (Ladies Side Saddle Attire) and HU130 (Ladies Side Saddle Tack and Equipment). These are the rules governing formal hunt seat appointments classes. Note helmets are now required at all times when mounted, even in the appointments class.
"All horses must be ridden astride." Side saddle is not permitted.
Side saddle is permitted, and a whip may be carried. The"rider must wear an apron of closed or button type with belt under loops. It is suggested that an apron with waist band cut the same as chaps and double thickness, be used in classes where chaps are required."
Side saddle (search on "sidesaddle") is accepted, and saddles and attire are described in detail.
SUBCHAPTER AR-3 PERFORMANCE CLASSES. AR112 General. 6. "Unless prohibited by section rules, Side saddles are permitted for ladies in all sections of the Arabian Division; appointments to be appropriate for the seat ridden" More specifics in later sections. Also refers to the Hunters section.
Side saddle classes may be held, but will not count toward Connemara HOTY awards
In Hunt Seat English Pleasure, Hunter Hack, Western Pleasure, and Costume, side saddle is permitted. Aside riders are allowed to carry one whip in all Dressage classes, including championship classes. (search on "sidesaddle")
SUBCHAPTER HK-15, HK148 General, PLEASURE HACKNEY HORSES 4. "Ladies are permitted to ride Sidesaddle in all ridden classes, with appropriate attire."
"Side saddle riders, in appropriate tack and attire, are allowed in all classes except equitation." Search on "side saddle"
Subchapter NS-10 describes sidesaddle classes, tack, and attire.
Side saddle permitted in Pleasure classes.
Side saddle permitted in western classes and Hunter Country Pleasure. Tack and attire is specified. Whips permitted in western.
Dressage, Chapter 5 specifically addresses side saddle riders, including some basic equitation and attire rules.. It permits side saddle riders to sit the trot in dressage tests, even when posting is normally called for. Side saddle riders may also carry a whip up to 120cm or cane up to 92cm at all levels. The dressage section contains extensive information about equipment and attire and some information about equitation. The eventing section also has a similar whip exception for side saddle riders.
British Show Horse Association
Includes brief class description and attire rules.
Side Saddle Association
Description of the many and varied saddle classes in the UK, including Concours d'Elegance and Historical.
Arabian Horse Association
Generally refers to USEF rules and ISSO resources.
North American Peruvian Horse Association
Part II Tack & Attire, Section 1 General a) Tack Overiew "Side saddle is permissible in any class except Bozal or as noted elsewhere or specified as an exception in the Premium List." Western and English tack rules refer to ISSO standards, while some detail is given on attire. Peruvian attire and tack is desscribed in detail. The Ladies Side Saddle class is described. Peruvian Side Saddle Equitation is described in great detail.
American Quarter Horse Association (AQHA)
AQHA bans side saddle riding, with a possible medical exception. Specifically, "SHW112.10 In all performance classes, horses are to be ridden astride, except in pleasure driving where they will be driven, and in showmanship where they are led with a halter."