Dressage term Wanna Be. These terms are partially put in my words but taken from the Glossary of terms booklet supplied to competitors from the USDF United States Dressage Federation. Contact them for an official copy. Reach refers to the forward extension of the forelegs, hind limbs, and neck of the horse. This term can refer to all of these or each one indivigually.
Regularity refers to the correctness of a gait, including purity, evenness and levelness.
Irregularities may be momentary or pervasive and they may or may not be caused by unsoundness. In the collective marks section on a dressage test, this term refers to only the purity and soundness of the gaits. This term has nothing to do with the right or wrong tempo. Often the physical and mental states go hand in hand. This term refers to physical opposition by the horse against the rider.