diff --git a/docs/releasenotes/10.4.0.rst b/docs/releasenotes/10.4.0.rst
index 0c2926732..3150bf4e0 100644
--- a/docs/releasenotes/10.4.0.rst
+++ b/docs/releasenotes/10.4.0.rst
@@ -23,6 +23,11 @@ TODO
 Deprecations
 ============
 
+BGR;15, BGR 16 and BGR;24
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The experimental BGR;15, BGR;16 and BGR;24 modes have been deprecated.
+
 Support for LibTIFF earlier than 4
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^