Compatibility map

[Marty Jack]

There is a part of the keyboard description called the Compatibility Map.  This is supposed to be for clients that predate Xkb, and gives rules for how to map Xkb modifier events onto pre-Xkb events.

It's also the case that is a huge part of the Xkb description, almost the size of the Geometry section that some have said is excess baggage these days.

It's been a few decades since we had a server/client that predated Xkb.  So the question is, how much of the Compatibility Map isn't excess baggage these days, and is there something essential that it must continue to do.