qmk_firmware-mirror/docs/quantum_keycodes.md

# Quantum Keycodes

Quantum keycodes allow for easier customisation 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

|Key          |Aliases    |Description                                                          |
|-------------|-----------|---------------------------------------------------------------------|
|`RESET`      |           |Put the keyboard into DFU mode for flashing                          |
|`DEBUG`      |           |Toggle debug mode                                                    |
|`KC_GESC`    |`GRAVE_ESC`|Escape when tapped, <code>&#96;</code> when pressed with Shift or GUI|
|`KC_LSPO`    |           |Left Shift when held, `(` when tapped                                |
|`KC_RSPC`    |           |Right Shift when held, `)` when tapped                               |
|`KC_LEAD`    |           |The [Leader key](feature_leader_key.md)                              |
|`KC_LOCK`    |           |The [Lock key](feature_key_lock.md)                                  |
|`FUNC(n)`    |`F(n)`     |Call `fn_action(n)` (deprecated)                                     |
|`M(n)`       |           |Call macro `n`                                                       |
|`MACROTAP(n)`|           |Macro-tap `n` idk FIXME                                              |