Check out this article for more: http://www.manjikai.com/strategy/strategy-blog/Hidden
# Doshi : I haven't seen those two documented in the article and they aren't in the movelist that you can cancel them halfway.They're footnotes in the English PDF move list on Tekken-net before the game came out. It's not in the in-game Command List though so that's why the confusion. These cancels have been around for a while now and they pop up as new information with the influx of newer Yoshi players.
Good on you for finding it though, there are still lots of unknowns out there so stay curious