RE: [css3 fonts] font-specific features

This is not directly related but allow me to use the opportunity
to ask the same dumb question I asked at Typecon: how do authors
find out about the features available in a font and the correct
integer values to use ?

Next question for the Web Fonts WG is: would an enumeration of
the features available in a font be a valuable use of the WOFF
metadata block ? I suspect it would make the latter far more
valuable to authors and thus add incentives for browser/tool
vendors to display its content.