diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index bdb61698a6f5fe82a4ebc30a0ef5df58ca93f4dc..0cfde1b5162db68f85d762f17fa34375ec09c9a0 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -9,6 +9,24 @@ and this project adheres to `Semantic Versioning`_.
 Unreleased
 ----------
 
+Notable, breaking changes
+~~~~~~~~~~~~~~~~~~~~~~~~~
+Starting from the class register core functionality, `AlekSIS-App-Alsijil` is getting a entire rewrite
+of both its frontend and backend. The models formerly used for lesson documentation, notably
+`LessonDocumentation` and `PersonalNote` are replaced by new ones based on the calendar framework
+provided by `AlekSIS-Core` and the absense framework provided by `AlekSIS-App-Kolego`. The legacy
+views providing management functionality for those legacy models are not available anymore. Currently,
+there exists no migration path away from legacy data.
+
+Changed
+~~~~~~~
+* Rewrite of class register/coursebook, both in the frontend and the backend
+  * Several legacy class register views were consolidated in one Vue.js based frontend (coursebook).
+  * [Dev] The `LessonDocumentation` model is replaced with the `Documentation` model, based on the calendar framework.
+  * [Dev] The `PersonalNote` model is replaced with the `NewPersonalNote` model.
+  * [Dev] Participation status documentation is taken over by the new `Participation` model.
+
+
 Fixed
 ~~~~~
 * Migrating failed due to an incorrect field reference.