diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index ffc40c98ae..8c3bbaa569 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -4152,6 +4152,20 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
             </glossdef>
         </glossentry>
 
+        <glossentry id='var-ROOTFS_POSTPROCESS_COMMAND'><glossterm>ROOTFS_POSTPROCESS_COMMAND</glossterm>
+            <glossdef>
+                <para>
+                    Added by classes to run post processing commands once the 
+                    OpenEmbedded build system has created the root filesystem.
+                    You can specify shell commands and, if necessary, the path
+                    to the root filesystem image:
+                    <literallayout class='monospaced'>
+     ROOTFS_POSTPROCESS_COMMAND += "${IMAGE_ROOTFS}&lt;shell_command&gt;; ... "
+                    </literallayout>
+                </para>
+            </glossdef>
+        </glossentry>
+
         <glossentry id='var-RPROVIDES'><glossterm>RPROVIDES</glossterm>
             <glossdef>
                 <para>