Data type: PtypString ([MS-OXCDATA] section 2.11.1)

The PidTagAnr property ([MS-OXPROPS] section 2.569) is a special property that is not actually a property on the Address Book objects themselves. Rather, this property is used by messaging clients as a property value in the Filter parameter of the NspiGetMatches method,<47> as specified in [MS-NSPI] and [MS-OXNSPI] section, or in the Filter field of the GetMatches request body,<48> as specified in [MS-OXCMAPIHTTP] section Messaging clients pass this property as a target string in the NspiGetMatches method or GetMatches request body to identify objects in an address list that are possible matches for the target string. This operation is known as ambiguous name resolution (ANR), as specified in [MS-NSPI] and [MS-OXNSPI] section<49> An address book server responds by returning the Minimal Entry IDs of all Address Book objects that are possible matches against the target string. This protocol does not prescribe the choice of ANR results of an address book server.<50>

An offline address book (OAB) does not contain this property for any Address Book objects. It is up to messaging clients to determine how to perform name matching among the objects in an OAB.