The Informational Flagging Protocol allows a user to mark an item for either follow-up or categorization. The marker is referred to as a flag. By flagging an item for follow up, the user can track the progress and completion of an associated work item. Categorizing items with flags enables a user to organize items in the user's mailbox. For example, users can assign start dates and due dates to their flagged items to prioritize their work, or they can assign a flag color to group related items.
This protocol specifies a set of properties that identify a Message object as being flagged. There are six different types of flags: basic flag, color flag, time flag, complete flag, recipient flag, and sender flag. A Message object that is delivered to a recipient and the sender's copy of that Message object can have their flag-related properties set independently of each other.
This protocol extends the Message and Attachment Object Protocol, described in [MS-OXCMSG], in that it adds capability for flagging a Message object.