1.8 Vendor-Extensible Fields

A third-party application can create its own set of named properties on a Message object as described in [MS-OXCPRPT]. A third-party application can also extend the Message and Attachment Object Protocol to implement its own object type by changing the PidTagMessageClass property (section For a simple example that extends this protocol to implement an electronic representation of a "Sticky Note", see [MS-OXONOTE].