diff --git a/en_US.ISO8859-1/books/porters-handbook/book.sgml b/en_US.ISO8859-1/books/porters-handbook/book.sgml
index 726f1aa235..41287ce11e 100644
--- a/en_US.ISO8859-1/books/porters-handbook/book.sgml
+++ b/en_US.ISO8859-1/books/porters-handbook/book.sgml
@@ -7527,6 +7527,12 @@ run_rc_command "$1"</programlisting>
 	substitution using &quot;:=&quot; would inappropriately
 	override the user's intention.</para>
 
+      <para>The suffix of the rc script is provided in
+	<makevar>RC_SUBR_SUFFIX</makevar> for further use in the port's
+	<filename>Makefile</filename>.  Current versions of &os; does not add
+	any suffix to the script name, but older versions has used to add
+	<filename>.sh</filename> suffix.</para>
+
       <sect2>
 	<title>Stopping services at deinstall</title>