/usr/share/X11/xkb/compat.dir is in xkb-data 2.5-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | -d------ -------- xtest(xtest)
-dp----- -------- pc(pc)
-dp----- -------- mousekeys(mousekeys)
-dp----- -------- iso9995(default)
-dp----- -------- ledscroll(scroll_lock)
--p----- -------- ledscroll(group_lock)
--p----- -------- ledscroll(shift_lock)
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