[uf-discuss] "uid" microformats?
Etan Wexler
ewexler at stickdog.com
Mon Apr 24 19:50:11 PDT 2006
Tantek Çelik wrote to the Microformats Discuss mailing list on
2006-04-19 in a message with a title like “[uf-discuss] UID, URL, live
microformats (was: Microformat auto-discovery WAS: Plazes &
Microformats)” (<mid:C06BB5C0.6CCEE%25tantek at cs.stanford.edu>,
<http://microformats.org/discuss/mail/microformats-discuss/2006-April/003726.html>):
> a UID is *supposed to* uniquely identify the contact or event,
> globally.
Section 3.6.7 of “vCard MIME Directory Profile” (RFC 2426,
<http://www.rfc-editor.org/rfc/rfc2426.txt>) defines the “UID” type:
> 3.6.7 UID Type Definition
>
> To: ietf-mime-directory at imc.org
>
> Subject: Registration of text/directory MIME type UID
>
> Type name: UID
>
> Type purpose: To specify a value that represents a globally unique
> identifier corresponding to the individual or resource associated
> with the vCard.
>
> Type encoding: 8bit
>
> Type value: A single text value.
>
> Type special notes: The type is used to uniquely identify the object
> that the vCard represents.
>
> The type can include the type parameter "TYPE" to specify the format
> of the identifier. The TYPE parameter value should be an IANA
> registered identifier format. The value can also be a non-standard
> format.
>
> Type example:
>
> UID:19950401-080045-40000F192713-0052
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, such use of a “UID” property is
incorrect. To do it right, a vCard publisher would make the “UID” value
a URI that identifies a person or an organization. The publisher would
also specify a “type=uri” parameter for the “UID” 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 “UID” type are to identify the subject of a vCard,
not to identify the authoritative version of a vCard. The “SOURCE” type
provides a semantics that comes close to identifying authoritative
version or versions. I suggest the use of the “SOURCE” type if we need
to find a ready solution within RFC 2426 or RFC 2425. (Also consider an
XMDP defining an “authority” or “authoritative-version” value for the
“rel” attribute.)
Section 6.1 of “A MIME Content-Type for Directory Information” (RFC
2425, <http://www.rfc-editor.org/rfc/rfc2425.txt>):
> 6.1. SOURCE Type Definition
>
> To: ietf-mime-direct at imc.org
> Subject: Registration of text/directory MIME type SOURCE
>
> Type name: SOURCE
>
> Type purpose: To identify the source of directory information
> contained in the content type.
>
> Type encoding: 8bit
>
> Type valuetype: uri
>
> Type special notes: The SOURCE type is used to provide the means by
> which applications knowledgable in the given directory service
> protocol can obtain additional or more up-to-date information from
> the directory service. It contains a URI as defined in [RFC-1738]
> and/or other information referencing the directory entity or entities
> to which the information pertains. When directory information is
> available from more than one source, the sending entity can pick what
> it considers to be the best source, or multiple SOURCE types can be
> included. The interpretation of the value for a SOURCE type can
> depend on the setting of the CONTEXT type parameter. The value of the
> CONTEXT type parameter MUST be compatible with the value of the uri
> prefix.
>
> Type example:
> SOURCE;CONTEXT=LDAP:ldap://ldap.host/cn=Babs%20Jensen,
> %20o=Babsco,%20c=US
>
The “SOURCE” type pretty well hits the nail on the head.
--
Etan Wexler.
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