diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index 7b1aef08c3..8650efabd9 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -10178,6 +10178,18 @@ recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3"
                     Thus, the <filename>RDEPENDS</filename> variable has the
                     <filename>${PN}-dev</filename> package name as part of the
                     variable.
+                    <note>
+                        <title>Caution</title>
+                        <filename>RDEPENDS_${PN}-dev</filename> includes
+                        <filename>${</filename><link linkend='var-PN'><filename>PN</filename></link><filename>}</filename>
+                        by default.
+                        This default is set in the BitBake configuration file
+                        (<filename>meta/conf/bitbake.conf</filename>).
+                        Be careful not to accidentally remove
+                        <filename>${PN}</filename> when modifying
+                        <filename>RDEPENDS_${PN}-dev</filename>.
+                        Use the "+=" operator rather than the "=" operator.
+                    </note>
                 </para>
 
                 <para>