diff --git a/documentation/ref-manual/ref-classes.xml b/documentation/ref-manual/ref-classes.xml
index 0626e6cc75..ce76140edd 100644
--- a/documentation/ref-manual/ref-classes.xml
+++ b/documentation/ref-manual/ref-classes.xml
@@ -579,6 +579,26 @@
     <para>
         The <filename>distrodata</filename> class
         provides for automatic checking for upstream recipe updates.
+        The class creates a comma-separated value (CSV) spreadsheet that
+        contains information about the recipes.
+        The information provides the <filename>distrodata</filename> and
+        <filename>distro_check</filename> tasks, which do upstream checking
+        and also verify if a package is used in multiple major distributions.
+    </para>
+
+    <para>
+        The class is not included by default.
+        To use it, you must include the following files and set the
+        <link linkend='var-INHERIT'><filename>INHERIT</filename></link>
+        variable:
+        <literallayout class='monospaced'>
+     include conf/distro/include/distro_alias.inc
+     include conf/distro/include/recipe_color.inc
+     include conf/distro/include/maintainers.inc
+     include conf/distro/include/upstream_tracking.inc
+     include conf/distro/include/package_regex.inc
+     INHERIT+= "distrodata"
+        </literallayout>
     </para>
 </section>