diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index e5b4db5f13..a862267769 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -3557,6 +3557,18 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
             </glossdef>
         </glossentry>
 
+        <glossentry id='var-SYSROOT_PREPROCESS_FUNCS'><glossterm>SYSROOT_PREPROCESS_FUNCS</glossterm>
+            <glossdef>
+                <para>
+                    A list of functions to execute after files are staged into 
+                    the sysroot.
+                    The OpenEmbedded build system usually uses such functions 
+                    to apply additional processing on the
+                    staged files, or to stage additional files.
+                </para>
+            </glossdef>
+        </glossentry>
+
     </glossdiv>
 
     <glossdiv id='var-glossary-t'><title>T</title>