diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 2bd3a27a94..b57c7bd344 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -3148,6 +3148,25 @@
             </glossdef>
         </glossentry>
 
+        <glossentry id='var-IMAGE_DEVICE_TABLES'><glossterm>IMAGE_DEVICE_TABLES</glossterm>
+            <glossdef>
+                <para>
+                    Specifies one or more files that contain custom device
+                    tables that are passed to the
+                    <filename>makedevs</filename> command as part of creating
+                    an image.
+                    These files list basic device nodes that should be
+                    created under <filename>/dev</filename> within the image.
+                    If <filename>IMAGE_DEVICE_TABLES</filename> is not set,
+                    <filename>files/device_table-minimal.txt</filename> is
+                    used.
+                    For details on how you should write device table files,
+                    see the <filename>files/device_table-minimal.txt</filename>
+                    as an example.
+                </para>
+            </glossdef>
+        </glossentry>
+
         <glossentry id='var-IMAGE_FEATURES'><glossterm>IMAGE_FEATURES</glossterm>
             <glossdef>
                 <para>