1<?xml version="1.0"?>
2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
3<html xmlns="http://www.w3.org/1999/xhtml">
4  <body>
5    <h1><abbr>a</abbr> b</h1>
6  </body>
7</html>
8