[foaf-dev] beyond foaf:mbox_sha1sum

Richard Cyganiak richard at cyganiak.de
Sat Dec 19 22:30:05 CET 2009

On 19 Dec 2009, at 20:54, Dan Brickley wrote:
> BTW http://www.w3.org/2003/06/sw-vocab-status/ns# is updated to
> mention the new value 'archaic'; and I'm looking into getting a tiny
> W3C SWIG Note drafted, since lots of namespaces use that vocab.

That would be great!

>> I still think that the property is useful for translating mailing  
>> list
>> archives to RDF, for example. The text should not be so alarmist  
>> that it
>> discourages such uses.
> This is a good use case, at least for publically archived mailing
> lists.

Yes, that was the case I was thinking of.

>>> 4. encourage data publishers to assign URIs to account holders
>>> directly, to indicate openID URIs and other identifying properties  
>>> as
>>> users permit
>> +1. Remember that “blank node + foaf:mbox_sha1sum + smushing” was  
>> considered
>> pretty much the canonical way of doing distributed identification  
>> in FOAF.
> That's a bit of an overstatement; but yes, it did become very popular,
> I think mostly because of foaf-a-matic.
> http://lists.foaf-project.org/pipermail/foaf-dev/2003-July/005463.html
> is the canonical statement on 'identifying things in foaf' from 2003.
> Extract,
> "This is one of the design principles underlying FOAF (and for that
> matter the entire Semantic Web effort): a pragmatic, pluralistic
> approach to resource description and identification. Rather than
> building big, centralised registries of people (or companies, or
> physical things) we look for cheaper, more lightweight shared  
> strategies
> for identification. In FOAF, we do this by making sure there are
> multiple ways we can identify things."
> This was in large part a response to early year accusations against
> RDF that it was hopelessly naive since it allegedly assumed that
> everything will have a globally known URI. So we took care to show
> that RDF can deal with heterogeneity and that multiple compatible
> mechanisms can be plugged together.

Interesting how things have changed...

I mostly meant to point out that the mbox_sha1sum+smushing idiom is a  
very visible one, probably because of FOAF-a-matic but also because  
it's used frequently as an example of reasoning/inference on the web.  
So it might be a good idea to still mention it in the spec, and point  
out that the idiom is now considered somewhat archaic, and that it  
used to be an IFP but is not any more.

>> Tangent: I find mbox_sha1sum useful for adding former email  
>> addresses that I
>> no longer use to my FOAF file. The hashes can still be used for  
>> smushing,
>> but no one would mistake the old email addresses as being current.  
>> That's
>> something I could not do with foaf:mbox alone. Is there a case for  
>> a new
>> property or some sort of new idiom here?
> In http://danbri.org/foaf.rdf I use
>    <mbox>
>      <rdf:Description rdf:about="mailto:danbri at w3.org">
>        <dct:isReplacedBy rdf:resource="mailto:danbri at danbri.org"/>
>      </rdf:Description>
>    </mbox>

I don't like this too much because the old address will still come up  
when querying for your foaf:mbox.

Adding foaf:deprecatedMbox is probably not a good idea, reflecting on  
the recent current/pastProject discussion.

I don't have any other good ideas for this. Using a hash to obfuscate  
the old address is of course not exactly the pinnacle of elegance  


> This is a bit verbose (and it indirectly keeps the old form in
> circulation). Wonder if it's nicer in RDFa.
> cheers,
> Dan
>> Best,
>> Richard
>> [1] http://pedantic-web.org/fops.html#ifps
>>> cheers,
>>> Dan
>>> _______________________________________________
>>> foaf-dev mailing list
>>> foaf-dev at lists.foaf-project.org
>>> http://lists.foaf-project.org/mailman/listinfo/foaf-dev

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