2.2.4 PidTagEntryId Property
Type: PtypBinary ([MS-OXCDATA] section 2.11.1)
The PidTagEntryId property ([MS-OXPROPS] section 2.674) identifies the Address Book object that specifies a user. The first two bytes of this property specify the number of bytes that follow. The remaining bytes constitute the PermanentEntryID structure ([MS-OXNSPI] section 22.214.171.124).
If the PidTagMemberId property (section 2.2.5) is set to one of the two reserved values, the first two bytes of this property MUST be 0x0000, indicating that zero bytes follow (that is, no PermanentEntryID structure follows the first two bytes).