diff --git a/CHANGES b/CHANGES
index c4b4db394e..effcf1e8b1 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,5 +1,7 @@
-4108.	[func]		A additional nxdomain redirect (nxdomain-redirect)
-			is now supported. [RT #37989]
+4108.	[func]		An additional NXDOMAIN redirect method (option
+			"nxdomain-redirect") has been added, allowing
+			redirection to a specified DNS namespace instead
+			of a single redirect zone. [RT #37989]
 
 4107.	[bug]		Address potential deadlock when updating zone content.
 			[RT #39269]
diff --git a/doc/arm/notes.xml b/doc/arm/notes.xml
index cbde1d9c52..012bcf6dd8 100644
--- a/doc/arm/notes.xml
+++ b/doc/arm/notes.xml
@@ -347,6 +347,19 @@
 	  server via TCP. [RT #37800]
 	</para>
       </listitem>
+      <listitem>
+	<para>
+	  The <command>nxdomain-redirect</command> option specifies
+	  a DNS namespace to use for NXDOMAIN redirection. When a 
+	  recursive lookup returns NXDOMAIN, a second lookup is
+	  initiated with the specified name appended to the query
+	  name. This allows NXDOMAIN redirection data to be supplied
+	  by multiple zones configured on the server or by recursive
+	  queries to other servers. (The older method, using
+	  a single <command>type redirect</command> zone, has
+	  better average performance but is less flexible.) [RT #37989]
+	</para>
+      </listitem>
     </itemizedlist>
   </sect2>
   <sect2 id="relnotes_changes">