some comments for WCAG 2

Version http://www.w3.org/WAI/GL/WCAG20/WD-WCAG20-20020828.html

There is a lot of good content in this document. The main principles are 
OK, some explanations may be fine tuned a bit e.g.
Operable. Ensure that the interface elements in the content are operable by 
any user
@@what about various devices? also preventing errors would be good to 
mention somewhere?@@.

Navigable. Facilitate content orientation and navigation
@@with spatial and sequential means?@@

Also the general checkpoints seem to be pretty reasonable.

My main concern is the definition of conformance levels. I think it is very 
difficult to do it for each general checkpoint as it is so abstract. The 
conformance levels become very artificial or are empty as it is hard to 
think what to put there. It would be much easier to do the conformance for 
the various mark-up languages and it might also make the transition from 
WCAG 1 to WCAG 2 easier. It would mean that we need to do updates for each 
language, which we probably would do anyway.

Another alternative is to divide the checkpoints for more and less 
important ones as we did before  in WCAG 1 but also that seems to be 
difficult in the general level.

Marja