IETF RFC 2739 PDF

When scheduling a calendar entity, such as an event, it is a prerequisite that an organizer has the calendar address of each attendee that will be invited to the event. Additionally, access to an attendee's current "busy time" provides an a priori indication of whether the attendee will be free to participate in the event.

In order to meet these challenges, a calendar user agent (CUA) needs a mechanism to locate (URI) individual user's calendar and free/busy time.

This memo defines three mechanisms for obtaining a URI to a user's calendar and free/busy time. These include:

- Manual transfer of the information;

- Personal data exchange using the vCard format; and

- Directory lookup using the LDAP protocol.