diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index c99f7362c3..ebdc554219 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -5602,6 +5602,21 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
             </glossdef>
         </glossentry>
 
+        <glossentry id='var-SDK_DEPLOY'><glossterm>SDK_DEPLOY</glossterm>
+            <glossdef>
+                <para>
+                    The temporary work directory set up and used by the
+                    <link linkend='ref-classes-populate-sdk'><filename>populate_sdk_base</filename></link>
+                    in which the SDK is deployed.
+                    The <filename>populate_sdk_base</filename> class defines
+                    <filename>SDK_DEPLOY</filename> as follows:
+                    <literallayout class='monospaced'>
+     SDK_DEPLOY = "${<link linkend='var-TMPDIR'>TMPDIR</link>}/deploy/sdk"
+                    </literallayout>
+                </para>
+            </glossdef>
+        </glossentry>
+
         <glossentry id='var-SDK_DIR'><glossterm>SDK_DIR</glossterm>
             <glossdef>
                 <para>