diff --git a/documentation/poky-ref-manual/ref-variables.xml b/documentation/poky-ref-manual/ref-variables.xml
index 7d60758226..2baed3788c 100644
--- a/documentation/poky-ref-manual/ref-variables.xml
+++ b/documentation/poky-ref-manual/ref-variables.xml
@@ -456,7 +456,20 @@
 
         <glossentry id='var-DISTRO'><glossterm>DISTRO</glossterm>
             <glossdef>
-                <para>The short name of the distribution.</para>
+                <para>
+                    The short name of the distribution. 
+                    This variable corresponds to a file with the
+                    extension <filename>.conf</filename>
+                    located in a <filename>conf/distro</filename> directory
+                    within the metadata that contains the distribution configuration. 
+                    The
+                    value must not contain spaces, and is typically all lower-case.
+                </para>
+                <para>
+                    If the variable is blank, a set of default configuration
+                    will be used, which is specified
+                    within <filename>meta/conf/distro/defaultsetup.conf</filename>.
+                </para>
             </glossdef>
         </glossentry>