diff --git a/nixos/doc/manual/release-notes/rl-unstable.xml b/nixos/doc/manual/release-notes/rl-unstable.xml
index cd828dfc8887..ffe8171171ac 100644
--- a/nixos/doc/manual/release-notes/rl-unstable.xml
+++ b/nixos/doc/manual/release-notes/rl-unstable.xml
@@ -145,6 +145,26 @@ nginx.override {
     from the ELPA, MELPA, and MELPA Stable repositories.
     </para>
   </listitem>
+
+  <listitem>
+    <para>CUPS, installed by <literal>services.printing</literal> module, now
+    has its data directory in <filename>/var/lib/cups</filename>. Old
+    configurations from <filename>/etc/cups</filename> are moved there
+    automatically, but there might be problems. Also configuration options
+    <literal>services.printing.cupsdConf</literal> and
+    <literal>services.printing.cupsdFilesConf</literal> were removed
+    because they had been allowing one to override configuration variables
+    required for CUPS to work at all on NixOS. For most use cases,
+    <literal>services.printing.extraConf</literal> and new option
+    <literal>services.printing.extraFilesConf</literal> should be enough;
+    if you encounter a situation when they are not, please file a bug.</para>
+
+    <para>There are also Gutenprint improvements; in particular, a new option
+    <literal>services.printing.gutenprint</literal> is added to enable automatic
+    updating of Gutenprint PPMs; it's greatly recommended to enable it instead
+    of adding <literal>gutenprint</literal> to the <literal>drivers</literal> list.
+    </para>
+  </listitem>
 </itemizedlist>