Taegeuk 2 Jang

Taegeuk 2 Jang symbolizes the "Tae", one of the 8 divination signs, which signifies the inner firmness and the outer softness. An introduction of the olgul-makki is a new development of Taegeuk poomsae. The ap-chagi actions appear more frequently than in Taegeuk 1 Jang. The 7th Kup-grade trainees practice this poomsae. 

http://www.wtf.org/wtf_eng/site/about_taekwondo/poomsae.html