Default subject (part of your last call comment, ISSUE-77)

Harry,

this is a request for clarification. For ISSUE-77 I have added, as explanation, your text:

[[[
Adding in extra blank node default subjects as a feature of RDF
Profiles vocabularies, i.e. to make vocabularies like OGP produce valid
triples. Note that in some instances of RDFa processing the profile is
retrieved anyways, so might as well make it do very useful things.
]]]

But I must admit I do not fully understand what you mean. Do you mean to define, say, for <head> an automatic default subject in the form of a new blank node?

If this is what you mean... The problem is that, at this moment, there *is* a default subject, namely the document itself. The typical @rel relationships, that are used in the <head>, like 'stylesheet' or 'copyright', make sense only for that subject, and they obviously would not make any sense for a separate blank node. This also means that we would seriously break deployed RDFa code.

Another way of interpreting what you say is that a profile would/could also define a default subject. While that might be clear when the profile is used on <html> or even on <head> or <body>, it becomes a bit difficult if the profile is used somewhere down the XML hierarchy. But I am also not sure this would solve the Facebook issue, unless Facebook is ready to deploy a separate facebook profile. Other than that, this should be part of the default profile of HTML, in which case we would fall back on the previous problem...

I may misunderstood what you meant, though.

Thanks

Ivan


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Ivan Herman, W3C Semantic Web Activity Lead
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Received on Friday, 21 January 2011 10:47:47 UTC