#data
<img decoding="" src="x"
  xmlns="http://www.w3.org/1999/xhtml" alt="x"/>
#errors
/img/@decoding;enumerated:invalid;m

#data
<img decoding="sync" src="x"
  xmlns="http://www.w3.org/1999/xhtml" alt="x"/>
#errors

#data
<img decoding="async" src="x"
  xmlns="http://www.w3.org/1999/xhtml" alt="x"/>
#errors

#data
<img decoding="auto" src="x"
  xmlns="http://www.w3.org/1999/xhtml" alt="x"/>
#errors

#data
<img decoding="synchronous" src="x"
  xmlns="http://www.w3.org/1999/xhtml" alt="x"/>
#errors
/img/@decoding;enumerated:invalid;m

#data
<img decoding="asynchronous" src="x"
  xmlns="http://www.w3.org/1999/xhtml" alt="x"/>
#errors
/img/@decoding;enumerated:invalid;m

#data
<img decoding="yes" src="x"
  xmlns="http://www.w3.org/1999/xhtml" alt="x"/>
#errors
/img/@decoding;enumerated:invalid;m