The attOwner attribute is encoded as counted strings laid end-to-end. The format for attOwner is as follows:
Unlike other length values, the display-name-length and address-length are unsigned 16-bit values instead of unsigned long integers. They still include terminating null characters, however. The type and address strings in the email-address entry are separated by a literal colon (:) character, such as "smtp:joe@nowhere.com". Only the combined type:address string is null-terminated.
The mapping of MAPI properties to the attOwner attribute is dependent on the message class of the message being encoded. If the message is either a Microsoft Schedule+ meeting request or cancellation, then attOwner encodes one of the PR_SENT_REPRESENTING properties. If the message is a Microsoft Schedule+ meeting response of any type, then attOwner encodes one of the PR_RCVD_REPRESENTING properties.