1. One or more computer-readable media having thereon an address book update data structure, the address book update data structure comprising the following: a first data field comprising a configurable list of a plurality of attribute property identifications that represent all of the properties that would be present in a fully populated address book entry; and a second data field comprising contact data associated with an address book entry to be updated, wherein the contact data includes at least some of the properties that are identified by the configurable list.