diff --git a/en_US.ISO8859-1/books/handbook/serialcomms/chapter.sgml b/en_US.ISO8859-1/books/handbook/serialcomms/chapter.sgml
index 6e2004e888..ab395187b3 100644
--- a/en_US.ISO8859-1/books/handbook/serialcomms/chapter.sgml
+++ b/en_US.ISO8859-1/books/handbook/serialcomms/chapter.sgml
@@ -477,6 +477,10 @@ crw-rw----    1 uucp     dialer    28, 193 Feb 15 14:38 /dev/cuala1</screen>
       <primary>rc files</primary>
       <secondary><filename>rc.serial</filename></secondary>
     </indexterm>
+
+    <!-- XXX; /etc/rc.serial is gone in 5.1.
+      How do you set default parameters for these devices in 5.X ? -->
+
     <para>System-wide initialization of the serial devices is
       controlled in <filename>/etc/rc.serial</filename>.  This file
       affects the default settings of serial devices.</para>