arts style, to compete in WT events as long as he or she is a member of the WT Member National Association in his or her nation; this allows essentially anyone to compete in WT-sanctioned competitions. Other styles and hybrids An example of other styles of Taekwondo is Extreme Taekwondo: a complex version of World Taekwondo Federation, which combines elements from all Taekwondo styles, Tricking (martial arts), similarities from other martial arts There are hybrid martial arts that are not Taekwondo styles but combine techniques of Taekwondo with those of other martial arts. These include: Han Moo Do: Scandinavian martial art that combines Taekwondo, hapkido, and hoi jeon moo sool. Han Mu Do: Korean martial art that combines Taekwondo and hapkido. Teukgong Moosool: Korean martial art that combines elements of Taekwondo, hapkido, judo, kyuk too ki, and Chinese martial arts. Yongmudo: developed at Korea's Yong-In University, combines Taekwondo, hapkido, judo, and ssireum. Forms (patterns) Three Korean terms may be used with reference to Taekwondo forms or patterns. These forms are equivalent to kata in karate. Hyeong (sometimes romanized as hyung; hanja: 形, hangeul: 형) is the term usually used in traditional Taekwondo (i.e., 1950s–1960s styles of Korean martial arts). Poomsae (sometimes romanized as pumsae or poomse; hanja: 品勢, hangeul: 품새) is the term officially used by Kukkiwon/WT-style and ATA-style Taekwondo. Teul (officially romanized as tul; hangeul: 틀) is the term usually used in ITF/Chang Hon-style Taekwondo. A hyeong is a systematic, prearranged sequence of martial techniques that is performed either with or without the use of a weapon. In dojangs (Taekwondo training gymnasiums) hyeong are used primarily as a form of interval training that is useful in developing mushin, proper kinetics and mental and physical fortitude. Hyeong may resemble combat, but are artistically non-combative and woven together so as to be an effective conditioning tool. One's aptitude for a particular hyeong may be evaluated in competition. In such competitions, hyeong are evaluated by a panel of judges who base the score on many factors including energy, precision, speed, and control. In Western competitions, there are two general classes of hyeong: creative and standard. Creative hyeong are created by the performer and are generally acrobatic in nature and do not necessarily reflect the kinetic principles intrinsic in any martial system. Different Taekwondo styles and associations (ATA, ITF, GTF, WT, etc.) use different Taekwondo forms. Even within a single association, different schools