http://www.rfc-editor.org/rfc/rfc6715.txt
RFC 6715: vCard Format Extensions: Representing vCard Extensions Defined by the Open Mobile Alliance (OMA) Converged Address Book (CAB) Group, D. Cauchie, B. Leiba, K. Li2012-08-01T23:00:00-00:00This document defines extensions to the vCard data format for representing and exchanging certain contact information. The properties covered here have been defined by the Open Mobile Alliance (OMA) Converged Address Book group, in order to synchronize, using OMA Data Synchronization, contact fields that were not already defined in the base vCard 4.0 specification. [STANDARDS-TRACK]