We need SAX features to say a parser supports XML 1.1

I guess we will be needing SAX properties to handle
XML 1.1.

I suggest:

http://xml.org/sax/features/xml1.1  

which, if present and true, says that the parser supports XML 1.1.

http://xml.org/sax/features/normalization

which, if present and true, says that the parser
supports normalization checks.

Cheers
Rick