taekwondo1-7, Exercise 1: Taekkyeon today

Model answer:

Sport taekkyeon: a limited subset of techniques, grappling and kicking only; points for throwing or tripping the opponent, pushing them out of the ring, or kicks to the head; no hand strikes or headbutts; deliberate injury prohibited; often best of three falls.
Yetbeop ("old methods") taekkyeon: preserves and applies all aspects except joint locks in sparring; allowed techniques include punches, open-handed strikes, elbows, knees, kicks, throws and clinch fighting.

Widae Preservation Society vs KTF: the Society (followers of Song Deok-gi) keeps a purely traditional approach, does not teach the sport-science innovations of the mid-1980s and does not hold competitions; Widae uses no formal ranks. The KTF (founded 1991, largest, the only body recognised by the Ministry of Culture, Sports and Tourism) promotes taekkyeon as a non-violent folk game focused on kicking and standardises rules and referee guidelines.

Why more information is needed: there is no universal standard, ranks differ or do not exist, and sport, yetbeop and Widae versions differ, so a statement about "taekkyeon" should say which group or version it means.

Sources: Wikipedia, Taekkyeon.