diff --git a/CHANGES b/CHANGES
index 33e6f91b4c..a043f8630e 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,20 @@
+5106.	[experimental]	A new "plugin" mechanism has been added to allow
+			extension of query processing functionality through
+			the use of dynamically loadable libraries. A
+			"filter-aaaa.so" plugin has been implemented,
+			replacing the filter-aaaa feature that was formerly
+			implemented as a native part of BIND.
+
+			The "filter-aaaa", "filter-aaaa-on-v4" and
+			"filter-aaaa-on-v6" options can no longer be
+			configured using native named.conf syntax. However,
+			loading the filter-aaaa.so plugin and setting its
+			parameters provides identical functionality.
+
+			Note that the plugin API is a work in progress and
+			is likely to evolve as further plugins are
+			implemented. [GL #15]
+
 5105.	[bug]		Fix a race between process_fd and socketclose in
 			unix socket code. [GL #744]
 
diff --git a/doc/arm/notes.xml b/doc/arm/notes.xml
index 1b46a0a852..8d707fb2e0 100644
--- a/doc/arm/notes.xml
+++ b/doc/arm/notes.xml
@@ -153,6 +153,19 @@
 	  as described in RFC 7706. [GL #33]
 	</para>
       </listitem>
+      <listitem>
+	<para>
+	  A new <command>plugin</command> mechanism has been added to allow
+	  extension of query processing functionality through the use of
+	  external libraries. The new <filename>filter-aaaa.so</filename>
+	  plugin replaces the <command>filter-aaaa</command> feature that
+	  was formerly implemented as a native part of BIND.
+	</para>
+	<para>
+	  The plugin API is a work in progress and is likely to evolve
+	  as further plugins are implemented. [GL #15]
+	</para>
+      </listitem>
       <listitem>
 	<para>
 	  BIND now can be compiled against the <command>libidn2</command>
@@ -289,6 +302,18 @@
 	  the operating system, and it cannot be built without threads.
 	</para>
       </listitem>
+      <listitem>
+	<para>
+	  The <command>filter-aaaa</command>,
+	  <command>filter-aaaa-on-v4</command>, and
+	  <command>filter-aaaa-on-v6</command> options have been removed
+	  from <command>named</command>, and can no longer be
+	  configured using native <filename>named.conf</filename> syntax.
+	  However, loading the new <filename>filter-aaaa.so</filename>
+	  plugin and setting its parameters provides identical
+	  functionality.
+	</para>
+      </listitem>
       <listitem>
 	<para>
 	  <command>named</command> can no longer use the EDNS CLIENT-SUBNET