Re: The exact meaning of a 'global identifier' (itemid)

On Mon, Jun 9, 2014 at 6:09 PM, Gregg Kellogg <>

> Of course, anyone may interpret Microdata however they find useful; it
> would be nice to get some definitive interpretation from
> partners, but they've (collectively) never been forthcoming on what the
> real semantics of

 "For a large case of classes, the meaning of a term is its use
in the language.  And the meaning of itemid is sometimes explained by
pointing at a bear <>."

I don't think that it safe is in general to use itemid (or itemprop etc)
except with  an absolute url ,  since the base of a relative name may be
affected by redirects.  (It is possible that urn:isbn:978-867-5-309-X might
pass as an itemid, though only itemtypes are protected against being
automatically dereferenced).

Received on Monday, 9 June 2014 23:55:37 UTC