Another FYI:

If you make a hide pose, it's best to make an un-hide pose as well.   Looks just like the example, only the key word is "on" instead of "off."

And lastly....

Although there is not even an ad-hoc standard, many creators attempt to adhere to some variation of the below;

MAT poses change materials
MOR poses adjust morphs
SET poses are multi-function-poses, to change joint params...or hide/unhide body parts.

(Oh by the way...if you didn't figure it out already, a pose file is nothing but a text file -- normally .txt -- that's had the suffix .pz2 applied instead.)