+<!DOCTYPE html [
+ <!-- A subset of XHTML -->
+ <!ELEMENT html (head,body)>
+ <!ELEMENT head (title)>
+ <!ELEMENT title (#PCDATA)>
+ <!ELEMENT body (h1|p|br)*>
+ <!ELEMENT h1 (#PCDATA)>
+ <!ELEMENT p (#PCDATA)>
+ <!ELEMENT br EMPTY>
+]>
+
+<html>
+ <head>
+ <title>Software</title>
+ </head>
+
+ <body>