Proposal related to Guideline A.1.1

I have an action to:
@@JR@@ensure preview rendered view out clause is in the defn of user 
interface@@

Instead of making changes to the definition, I thought it might be 
better to address this elsewhere, so I propose to:

(1) add a note to A.?.4 "Ensure previews emulate accessible rendering 
features of browsers"

Note 1: This requirement serves in lieu of any other user interface 
accessibility requirements for the content view of built-in preview 
features only. The authoring tool user interface for built-in previews 
that is external to the content view must still meet the accessibility 
requirements in this document.

(2) add a note for all of section A:

Note: The requirement in this section apply to all parts of the 
authoring tool interface except for the content view of built-in preview 
features (see checkpoint A.?.4 for more information).

Cheers,
Jan