[uf-discuss] "uid" microformats?

Tantek Ç elik tantek at cs.stanford.edu
Tue Apr 25 07:43:29 PDT 2006

On 4/24/06 7:50 PM, "Etan Wexler" <ewexler at stickdog.com> wrote:

> Tantek Çelik wrote to the Microformats Discuss mailing list on
> 2006-04-19 in a message with a title like ³[uf-discuss] UID, URL, live
> microformats (was: Microformat auto-discovery WAS: Plazes &
> Microformats)² (<mid:C06BB5C0.6CCEE%25tantek at cs.stanford.edu>,
> <http://microformats.org/discuss/mail/microformats-discuss/2006-April/003726.h
> tml>):
>> a UID is *supposed to* uniquely identify the contact or event,
>> globally.
> Section 3.6.7 of ³vCard MIME Directory Profile² (RFC 2426,
> <http://www.rfc-editor.org/rfc/rfc2426.txt>) defines the ³UID² type:

Heh. I already quoted this in a latter message ;)

> Tantek asks:
>> In addition to marking up the authoritative/canonical URL for a
>> contact/event with class name of URL, why not also use that URL for the UID?
> Unless the hCard is about itself,

Etan, what do you mean by this?

> such use of a ³UID² property is
> incorrect.

Unless you can point to where in the definition of UID in RFC2426 it says
"you cannot use URLs", your assertion of incorrectness has no basis.

> To do it right, a vCard publisher would make the ³UID² value
> a URI that identifies a person or an organization.

s/URI/URL and you got it.

> The publisher would
> also specify a ³type=uri² parameter for the ³UID² property.


>> As far as I can tell, this should work perfectly to answer the question of
>> "What do do about UID?".
> The semantics of the ³UID² type are to identify the subject of a vCard,
> not to identify the authoritative version of a vCard. The ³SOURCE² type
> provides a semantics that comes close to identifying authoritative
> version or versions. I suggest the use of the ³SOURCE² type if we need
> to find a ready solution within RFC 2426 or RFC 2425.
> The ³SOURCE² type pretty well hits the nail on the head.

No, there is a *very* big distinction that I think you may missed between

If I post an hCalendar vevent of an Upcoming.org event on my blog, the
SOURCE of that vevent is http://tantek.com (or the blog permalink), whereas
the URL+UID is an upcoming.org URL.

This distinction is very important, for web-based hCard/hCalendar processors
can automatically fill in the SOURCE using the URL where they found the
hCard or hCalendar, but they cannot automatically fill in the UID, as that
semantic is something only the publisher can declare.


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