Adding reference to Authoritative Metadata TAG finding

Hello WG.

In the Document Structure chapter, there’s a link to the “Authoritative
Metadata” TAG finding[1] in the description of type="" on <image>, but
there’s no corresponding entry in the References section.  I’ll add one,
but should it be a normative or informative reference?

Thanks,

Cameron

[1] http://www.w3.org/2001/tag/doc/mime-respect.html

-- 
Cameron McCormack ≝ http://mcc.id.au/