http://dublincore.org/documents/dcmi-terms/#terms-relation

"This term is intended to be used with non-literal values as defined
in the DCMI Abstract Model
(http://dublincore.org/documents/abstract-model/). As of December
2007, the DCMI Usage Board is seeking a way to express this intention
with a formal range declaration."

So if you use the dcterms namespace (rather than dc elements) you
should be fine.

-Ross.

On Thu, Jul 8, 2010 at 9:48 AM, Jonathan Rochkind <[log in to unmask]> wrote:
> In my experience, you can't tell much about what you'd really want to know
> for user needs from the indicators or subfield 3's, at least in my catalog.
> FRBR relationships probably don't work because the destination of an
> arbitrary 856 is not neccesarily a FRBR entity, and even if it is there's no
> way to know that (or what class of entity) from the data.  It really is just
> "generic some kind of related web page".
>
> So "dc:relation" does sound like the right vocabulary element for generic
> "related web page page", thanks.  Is the value of dc:relation _neccesarily_
> a URI/URL?  I hope so, because otherwise I'm not sure dc:relation is
> sufficient, as I really do need something that says "some related URL".
>
> Thanks for the advice,
>
> Jonathan
>
> Ed Summers wrote:
>>
>> On Wed, Jul 7, 2010 at 7:00 PM, Doran, Michael D <[log in to unmask]> wrote:
>>
>>>
>>> Of course, subfield $3 values are not any kind of controlled vocabulary,
>>> so it's hard to do much with them programmatically.
>>>
>>
>> A few years ago I analyzed the subfield 3 values in the Library of
>> Congress data up at the Internet Archive [1]. Of course it's really
>> simple to extract, but I just pushed it up to GitHub, mainly to share
>> the results [2].
>>
>> I extracted all the subfield 3 values from the 12M? records, and then
>> counted them up to see how often they repeated [3]. As you can see
>> it's hardly controlled, but it might be worthwhile coming up with some
>> simple heuristics and properties for the familiar ones: you could
>> imagine dcterms:description being used for "Publisher description",
>> etc.
>>
>> Of course the $3 in your catalog data might be different from LCs, but
>> maybe we could come up with a list of common ones on a wiki somewhere,
>> and publish a little vocabulary that covered the important relations?
>>
>> //Ed
>>
>> [1] http://www.archive.org/details/marc_records_scriblio_net
>> [2] http://github.com/edsu/beat
>> [3] http://github.com/edsu/beat/raw/master/types.txt
>>
>>
>