diff --git a/PendingReleaseNotes b/PendingReleaseNotes
index 91015cf7dd3f0..a5a20b9dbe62f 100644
--- a/PendingReleaseNotes
+++ b/PendingReleaseNotes
@@ -138,6 +138,7 @@
   `ceph config set mgr mgr/telemetry/leaderboard_description ‘Cluster description’`.
 * CEPHFS: After recovering a Ceph File System post following the disaster recovery
   procedure, the recovered files under `lost+found` directory can now be deleted.
+* core: cache-tiering is now deprecated.
 
 >=17.2.1
 
diff --git a/doc/rados/operations/cache-tiering.rst b/doc/rados/operations/cache-tiering.rst
index 8056ace4743bd..cd29b87d0cfa6 100644
--- a/doc/rados/operations/cache-tiering.rst
+++ b/doc/rados/operations/cache-tiering.rst
@@ -1,6 +1,10 @@
 ===============
  Cache Tiering
 ===============
+.. warning:: Cache tiering has been deprecated in the Reef release as it
+             has lacked a maintainer for a very long time. This does not mean
+             it will be certainly removed, but we may choose to remove it
+             without much further notice.
 
 A cache tier provides Ceph Clients with better I/O performance for a subset of
 the data stored in a backing storage tier. Cache tiering involves creating a