rgb keycodes

docs/ChangeLog/20241124.md

@@ -21,7 +21,13 @@ One note with updated keyboard names -- historical keyboard names are still cons
 
 In line with the [notice period](../support_deprecation_policy#how-much-advance-notice-will-be-given), deprecation notices for larger items are listed here.
 
-### ADNS9800 and PMW33xx sensor firmware ROM removal
+### RGB Keycode Overhaul ([#23679](https://github.com/qmk/qmk_firmware/pull/23679), [#24484](https://github.com/qmk/qmk_firmware/pull/24484), [#24490](https://github.com/qmk/qmk_firmware/pull/24490))
+
+RGB keycodes have been reworked to allow for both rgblight and rgb_matrix to coexist for the handful of boards in the repo with both enabled. Previously, `RGB_xxx` style keycodes were available, but now for rgblight we have `UG_xxx` (underglow), and `RM_xxx` for rgb_matrix. Default keymaps have been updated to reflect whichever system the respective board enables.
+
+Longer-term, `RGB_xxx` style keycodes will be removed, but for now they act as if they're `UG_xxx`, and `UG_xxx` keycodes act upon both rgblight and rgb_matrix simultaneously. Put simply, the existing `RGB_xxx` keycodes act as they always have, giving users time to transition across to the new keycodes instead.
+
+### ADNS9800 and PMW33xx sensor firmware ROM removal ([#24428](https://github.com/qmk/qmk_firmware/pull/24428))
 
 Following on from the last Breaking Changes cycle, Binary blobs for optical sensors have been removed from the QMK codebase. Hooks allowing users to supply their own have been put in place; users wishing to source firmware blobs and integrate them into their keymap may do so. Doing so renders their firmware un-distributable due to licensing incompatibility with the GPL -- as such user firmware containing such blobs must not be distributed.