Requirements comments

  Hi Gregory,

In general I like the requirements and I think they are clear.

Three suggestions:

1. I think there's one critical omission -- direct navigation.

Sequential navigation works well when the user is cycling through only a 
few elements. Requirements 5-9 cover this well. Sequential navigation 
worked well for jumping among web pages when there are only a few links 
on a page. This was the case in the early days of the web, but  many of 
today's web pages have tens or hundreds of elements including links, 
rendering sequential navigation tedious at best and unusable at worst.

The mouse gives users a good way to go directly to any element, 
sidestepping the issue for many users. But users who find it difficult 
or impossible to use the mouse cannot be expected to rely on sequential 
navigation for everything they do on the web. This can slow navigation 
by order of magnitude or more.

Direct navigation by keyboard to all the elements covered by sequential 
navigation is critical to make the web usable for those who cannot use a 
mouse. There's a good implementation example in Firefox: the Mouseless 
Browsing extension (https://addons.mozilla.org/en-US/firefox/addon/879/)

UAAG addresses this in 4.7.2, and 4.7.5, but the intent and examples 
have not yet been drafted.
4.7.2 Direct navigation: direct movement to important (structural and 
operable) elements 
<http://www.w3.org/WAI/UA/2010/ED-UAAG20-20100823/#def-important-elements> 
in rendered content is provided. (Level A).
4.7.5 Direct activation: direct movement to and activation of any 
operable elements in rendered content is provided. (Level AA)

2. Requirement 2 would enable users in a more powerful way if the 
default access mapping and user override mapping could be stored and shared.

3. Requirement 4 would enable users in a more powerful way
-  if the user overrides could also be described
- and if the descriptions could be stored and shared along with the mappings


References
- Requirements
http://www.w3.org/WAI/PF/HTML/wiki/Access/pf_requirements
- Pertinent parts of UAAG
http://www.w3.org/WAI/PF/HTML/wiki/Talk:Access/pf_requirements

Cheers,
Kim