18.104.22.168 PtypString8 (0x001E) Value Encoding
All narrow character set or multi-byte character set strings are encoded as byte sequences and MUST be terminated by a single 0x00 byte. A string sequence MUST NOT contain a 0x00 byte as part of the string itself. A zero length or empty string MUST NOT be encoded, but MUST be marked as not present in the presenceBitArray.
Properties whose data type is PtypEmbeddedTable ([MS-OXCDATA] section 2.11.1), and whose value represents a reference to at most one other Address Book object, are encoded using the PtypString8 value encoding. The string value MUST be a DN (3) for an Address Book object, which can be present in the OAB.
For more details about the PtypString8 data type, see [MS-OXCDATA] section 2.11.1.