When defining a keymap each key needs a valid key definition.
This page documents the symbols that correspond to keycodes that are available to you in QMK.
0x00 - 0xFF)Basic keycodes in QMK are based on HID Usage Keyboard/Keypad Page(0x07) with following exceptions:
KC_NO = 0 for no actionKC_TRNS = 1 for layer transparency0xA5-DF range (tmk heritage).0x0100 - 0xFFFF)Quantum keycodes allow for easier customisation of your keymap than the basic ones provide, without having to define custom actions.