This document says it "provides best practice guidance for authors," yet it describes approaches based on features which failed CR for lack of interoperable implementation, such as Detailsither it should describe only currently available approaches, or call itself something other than "best practices." Both cannot be tru at the same time. My suggestion is to remove the language referring to features which did not make the current PR draft, and also to point to the PR (and later the TR) version of HTML 5. The additional approaches can be returned to this document after V. 1.0 of this note is complete. Until then, they are inappropriate here..