# Keycodes Overview
When defining a [keymap](keymap.md) each key needs a valid key definition. This page documents the symbols that correspond to keycodes that are available to you in QMK.
This is a reference only. Each group of keys links to the page documenting their functionality in more detail.
## [Basic Keycodes](keycodes_basic.md)
|Key |Aliases |Description |
|-----------------------|------------------------------|-----------------------------------------------|
|`KC_NO` |`XXXXXXX` |Ignore this key (NOOP) |
|`KC_TRANSPARENT` |`KC_TRNS`, `_______` |Use the next lowest non-transparent key |
|`KC_A` | |`a` and `A` |
|`KC_B` | |`b` and `B` |
|`KC_C` | |`c` and `C` |
|`KC_D` | |`d` and `D` |
|`KC_E` | |`e` and `E` |
|`KC_F` | |`f` and `F` |
|`KC_G` | |`g` and `G` |
|`KC_H` | |`h` and `H` |
|`KC_I` | |`i` and `I` |
|`KC_J` | |`j` and `J` |
|`KC_K` | |`k` and `K` |
|`KC_L` | |`l` and `L` |
