Alters the keyboard LEDs without changing the operational state of the keyboard's mode of scan code generation. This IOCtl is reserved for use by the Presentation Manager session system and cannot be called by applications. Requests from applications return an UNKNOWN_COMMAND error.

Because it is not possible to separate the keyboard's LED and operational state for the 88/89-Key Enhanced Keyboard, the physical Keyboard device driver performs no operations for IOCtl requests received when the 88/89-Key Enhanced keyboard is the attached system keyboard.