diff --git a/documentation/ref-manual/ref-classes.xml b/documentation/ref-manual/ref-classes.xml
index 1ea2a3d84a..ae01bcec97 100644
--- a/documentation/ref-manual/ref-classes.xml
+++ b/documentation/ref-manual/ref-classes.xml
@@ -488,6 +488,17 @@
+
+ copyleft_filter.bbclass
+
+
+ A class used by the archiver and the
+ copyleft_compliance
+ classe for filtering licenses.
+ This is an internal class and is not intended to be used directly.
+
+
+
core-image.bbclass