how to get more keys support by TMK?

[tokyo]

Is there any way to support sending more keycodes (not physical keys on board) in TMK?

example:
  http://wiki.linuxquestions.org/wiki/XF86_keyboard_symbols
  http://cgit.freedesktop.org/xorg/proto/x11proto/tree/XF86keysym.h
  https://wiki.debian.org/Keyboard/MultimediaKeys

[hasu]

You can send HID usages in keyboard page. THose symbols are logical in Xorg environment, OS or Xorg convertes the usages into the smybols somewhere, I don't know more detail about it.

See pp53.
http://www.usb.org/developers/hidpage/Hut1_12v2.pdf