Not technically the encyclopedia, but in the 1968 version of Taekwon-do, General Choi wrote the following in Part 5, Patterns in Taekwon-do (hyong). "The following points must be borne in mind in performing the patterns: 1. Performance of each pattern must be ended at the starting point (x)." He then goes on to add another 5 points regarding how forms are to be performed. One caveat though is this is when there were only 20 defined patterns, consisting of Chon-ji, Tan-gun, To-san, Won-Hyo, Yul-Kok, Chung-Gun, Toi-Gye, Hwa-Rang, Chung-Mu, Kwang-Gae, Po-Un, Kae-Baek, Yu-Sin, Chung-Jang, Ul-Ji, Sam-Il, Choi-Yong, Ko-Dang, Se-Jong, and Tong-Il. There have been additions and modifications since 1968 as I know you are already aware.