diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 1c55a92d15..eeb2da8ddd 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -12193,11 +12193,30 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
             <glossdef>
                 <para role="glossdeffirst">
 <!--                <para role="glossdeffirst"><imagedata fileref="figures/define-generic.png" /> -->
-                    A list of variables not allowed through from the build
-                    system configuration into the extensible SDK configuration.
+                    A list of variables not allowed through from the
+                    OpenEmbedded build system configuration into the extensible
+                    SDK configuration.
                     Usually, these are variables that are specific to the
                     machine on which the build system is running and thus
                     would be potentially problematic within the extensible SDK.
+                    </para>
+
+                    <para>By default,
+                    <filename>SDK_LOCAL_CONF_BLACKLIST</filename> is set in the
+                    <link linkend='ref-classes-populate-sdk-*'><filename>populate-sdk-ext</filename></link>
+                    class and excludes the following variables:
+                    <literallayout class='monospaced'>
+     <link linkend='var-CONF_VERSION'>CONF_VERSION</link>
+     <link linkend='var-BB_NUMBER_THREADS'>BB_NUMBER_THREADS</link>
+     <ulink url='&YOCTO_DOCS_BB_URL;#var-BB_NUMBER_PARSE_THREADS'>BB_NUMBER_PARSE_THREADS</ulink>
+     <link linkend='var-PARALLEL_MAKE'>PARALLEL_MAKE</link>
+     <link linkend='var-PRSERV_HOST'>PRSERV_HOST</link>
+     <link linkend='var-SSTATE_MIRRORS'>SSTATE_MIRRORS</link>
+     <link linkend='var-DL_DIR'>DL_DIR</link>
+     <link linkend='var-SSTATE_DIR'>SSTATE_DIR</link>
+     <link linkend='var-TMPDIR'>TMPDIR</link>
+     <link linkend='var-BB_SERVER_TIMEOUT'>BB_SERVER_TIMEOUT</link>
+                    </literallayout>
                 </para>
             </glossdef>
         </glossentry>