setxkbmap -config file format is undocumented
Submitted by Alan Coopersmith
Assigned to Xorg Project Team
As noted in http://unix.stackexchange.com/q/167131/146 , the setxkbmap man page does not document the file format of the file passed for -config, and I can't find anywhere else in our docs, including all of the links on http://www.x.org/wiki/XKB/ that documents it either.
We really should give users some clue what to provide, once we figure out the details ourselves.