diff --git a/LDP/howto/linuxdoc/NET3-4-HOWTO.sgml b/LDP/howto/linuxdoc/NET3-4-HOWTO.sgml
index 0591953e..b75e7fc5 100644
--- a/LDP/howto/linuxdoc/NET3-4-HOWTO.sgml
+++ b/LDP/howto/linuxdoc/NET3-4-HOWTO.sgml
@@ -1,4 +1,4 @@
-<!doctype linuxdoc public "-//LinuxDoc//DTD LinuxDoc 97//EN">
+<!doctype linuxdoc system>
 
 <article>
 <title>Linux Networking-HOWTO (Previously the Net-3 Howto)