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RE: empty metadata elements

From: Jon Hanna <jon@spin.ie>
Date: Mon, 10 Feb 2003 16:20:31 -0000
To: <w3c-wai-ig@w3.org>
Message-ID: <NDBBLCBLIMDOPKMOPHLHCENLENAA.jon@spin.ie>

> Initially I thought the practice of making the statement that
> certain metadata was null was good but I can see at least one
> instance where it might not be. Are there any types of metadata
> where the lack of that positive statement would be more
> beneficial than detrimental. And vice versa?

The question is what does null mean in a particular context.

In some cases it will be a strong and useful assertion, in some cases it
will be one value but not necessarily the only value, and hence pointless,
in some cases it will be obviously untrue (meta name="DC.creator" content=""
/> is obviously wrong since someone or something created it).

If we take the example of something indicating WAI guideline compliance (the
wisdom and value of which would be another matter) then we could use 0 to
indicate a failure to comply at all, with possible values therefore of 0, 1,
2 or 3 a null value is clearly invalid and means that we do not have the
information in question.

In some cases the value of null can only be induced by use of a scheme along
with the name, or with a richer metadata mechanism (such as RDF).
Received on Monday, 10 February 2003 12:10:27 GMT

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