This is primarily for multi-valued string attributes, specifically proxy Addresses.In this case, Address Book Server is interested only in proxy Addresses entries that begin with "tel:".For example, if the ms RTCSIP-Primary User Address attribute has this flag bit set, then contacts that have this attribute are not written to the database.
A string attribute, but is included only if the attribute value begins with "tel:".
Lync Server requires standardized RFC 3966/E.164 phone numbers.
To use phone numbers that are unstructured or inconsistently formatted, Lync Server relies on the Address Book Server to preprocess phone numbers before they are handed off to the normalization rules.
The schema for the Ab User Entry table uses two columns, User Guid and User Data.
User Guid is the index column and contains the 16-byte GUID of the Active Directory object.