diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 5661a86907..5556e56cba 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -1855,6 +1855,13 @@
                     Use this variable when the arguments need to be after the
                     <filename>.pro</filename> file list on the command line.
                 </para>
+
+                <para>
+                    This variable is is used with recipes that inherit the
+                    <link linkend='ref-classes-qmake_base'><filename>qmake_base</filename></link>
+                    class or other classes that inherit
+                    <filename>qmake_base</filename>.
+                </para>
             </glossdef>
         </glossentry>
 
@@ -1866,6 +1873,13 @@
                     Use this variable when the arguments need to be before the
                     <filename>.pro</filename> file list on the command line.
                 </para>
+
+                <para>
+                    This variable is is used with recipes that inherit the
+                    <link linkend='ref-classes-qmake_base'><filename>qmake_base</filename></link>
+                    class or other classes that inherit
+                    <filename>qmake_base</filename>.
+                </para>
             </glossdef>
         </glossentry>