qmk_firmware/docs/quantum_keycodes.md

Quantum Keycodes

Quantum keycodes allow for easier customization of your keymap than the basic ones provide, without having to define custom actions.

All keycodes within quantum are numbers between 0x0000 and 0xFFFF. Within your keymap.c it may look like you have functions and other special cases, but ultimately the C preprocessor will translate those into a single 4 byte integer. QMK has reserved 0x0000 through 0x00FF for standard keycodes. These are keycodes such as KC_A, KC_1, and KC_LCTL, which are basic keys defined in the USB HID specification.

On this page we have documented keycodes between 0x00FF and 0xFFFF which are used to implement advanced quantum features. If you define your own custom keycodes they will be put into this range as well.

QMK Keycodes :id=qmk-keycodes

Key	Aliases	Description
QK_BOOTLOADER	QK_BOOT	Put the keyboard into bootloader mode for flashing
QK_DEBUG_TOGGLE	DB_TOGG	Toggle debug mode
QK_CLEAR_EEPROM	EE_CLR	Reinitializes the keyboard's EEPROM (persistent memory)
QK_MAKE		Sends qmk compile -kb (keyboard) -km (keymap), or qmk flash if shift is held. Puts keyboard into bootloader mode if shift & control are held
QK_REBOOT	QK_RBT	Resets the keyboard. Does not load the bootloader