"AMSL" can also be abbreviated to just "MSL".
A good point and known acronym term.
That would be good for a boating forum, but mostly we are concerned with the 'above' aspect of sea level.
. . . and then, if concerned or needed at all really, mostly we are only really concerned with AGL.
ASL is more handy, if flying over the ocean, and merely means distance form sea / water surface to the aircraft.
MSL could be added I suppose, no harm, just can't see it relating to any sort of drone situation as we fly at many other times than MSL.
Edit - I see MSL is there on the list, might have been added in the past 15 minutes
------------------
Good list.
Obviously unofficial some of it, or at least purely drone orientated.
In this case, I've always liked someones post here once (and it seemed to catch on) where they mentioned the term / acronym ATOP, for Above Take Off Point.
This is obviously very specific to many drone posts, handy to discern differences in flight analysis etc, and could be worthy of addition.
It maybe be on the list on some other form / wording, but having it in the 'A' section with AGL, AMSL etc is going to be easier to relate to altitude.
The trick is though, how to get anyone wondering 'what acronym = what' is getting them to know there is an acronym wiki on the forum.