Internal Program Version: xkeyboard-config  2.38

The X Keyboard Extension essentially replaces the core protocol
definition of keyboard. The extension makes possible to clearly and
explicitly specify most aspects of keyboard behaviour on per-key basis
and to more closely track the logical and physical state of the
keyboard. It also includes a number of keyboard controls designed to
make keyboards more accessible to people with physical impairments.

http://www.freedesktop.org/Software/XKeyboardConfig