Calendar Attributes for vCard and LDAP
updated by
- rfc-6350 — vCard Format Specification
Extracted elements (17)
The 'default' calendar concept is introduced to simplify multi-calendar scenarios. A user designates one calendar (possibly an aggregation of all others) as the default that other users should consult, identified by the PREF parameter on the relevant vCard property.
Three distribution mechanisms are defined for calendar URIs—manual transfer, vCard exchange, and LDAP directory lookup—to accommodate varying deployment environments from simple personal exchange to enterprise directory integration.
URIs found via LDAP directory lookup should generally be considered more up-to-date than URIs stored in locally cached vCards, because directory entries can be updated centrally.
If the CALURI is an HTTP URI, the content returned with a GET SHOULD be a 'text/calendar' MIME body part. If it is an FTP URI, the resource SHOULD be a file with an 'ics' extension.
If the FBURL points to a file or document resource, its file extension SHOULD be 'ifb' to distinguish it from a generic iCalendar object (which uses 'ics').
It is RECOMMENDED that the previous six weeks of busy time data be published at the FBURL location.
When multiple FBURL, CALURI, CALADRURI, or CAPURI properties are present in a vCard, the default property MUST be indicated using the PREF parameter.
CALADRURI is a URI specifying the location to which an event request should be sent for a user. It is analogous to an email address but for calendar scheduling requests.
CALURI (Calendar URI) is a protocol-independent URI from which a CUA can retrieve a snapshot of a user's entire calendar. HTTP URIs return 'text/calendar' MIME content; FTP URIs point to a file with '.ics' extension.
CAPURI (Calendar Access URI) is a protocol-independent URI from which a CUA can communicate with a user's entire calendar. Semantics for using this URI as an access protocol locator are deferred to the Calendar Access Protocol specification.
Eight LDAP attributes are defined: calCalURI (OID .478), calFBURL (.479), calCAPURI (.480), calCalAdrURI (.481), calOtherCalURIs (.482), calOtherFBURLs (.483), calOtherCAPURIs (.484), calOtherCalAdrURIs (.485). All use IA5String syntax with caseIgnoreMatch equality. The calOther* attributes are MULTI-VALUE.
FBURL (Free/Busy URI) is a transport-independent URI pointing to a user's busy time data. Retrieving it via HTTP or FTP returns an iCalendar object containing one or more VFREEBUSY components in a 'text/calendar' MIME body part.
The LDAP calEntry object class (OID 1.2.840.113556.1.5.87) is an AUXILIARY class derived from TOP that MAY contain calCalURI, calFBURL, calOtherCalURIs, calOtherFBURLs, calCAPURI, and calOtherCAPURLs attributes.
This document registers four new vCard property types with the text/directory MIME type registration agent (ietf-mime-directory@imc.org): FBURL, CALADRURI, CAPURI, and CALURI.
This document registers LDAP schema extensions: one object class (calEntry) and eight attributes (calCalURI, calFBURL, calCAPURI, calCalAdrURI, calOtherCalURIs, calOtherFBURLs, calOtherCAPURIs, calOtherCalAdrURIs) under the 1.2.840.113556 OID arc.
Information obtained from directory servers supplied by clients may be out of date; for example, dynamically assigned IP addresses stored in the directory may have been reassigned to a different host. This issue is not specific to LDAP or dynamic directories.
LDAP servers may permit anonymous clients to refresh entries they did not create, which has implications for data integrity. Servers may require clients to bind before issuing a RefreshRequest, impacting performance and scalability. vCard objects may have been created by an entity other than the one they represent, so recipients should verify the vCard source.