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