As far as I am aware, the ESOUIDocumentation.txt is just a dump of their internal wiki or something. Probably a sideproduct written by some humans, so like almost every documentation on earth it won't reflect what is really in the game. Your best bet is to use Ayantir's
Dumper addon and only use the txt as a reference for what you have in the dump. The stuff that is missing after you did that, you will have to check against what is in the wiki and the ui source code, or just experiment with it ingame.