OAL data sequence number: An integer that is associated with offline address list (OAL) data that represents the generation number of this data. The value of the initial sequence number is "1". Each subsequent data generation process that produces a data set that is not identical to the previous data set is incremented by one.
Object Linking and Embedding (OLE): A technology for transferring and sharing information between applications by inserting a file or part of a file into a compound document. The inserted file can be either embedded or linked. See also embedded object and linked object.
offline: The condition of not being connected to or not being on a network or the Internet. Offline can also refer to a device, such as a printer, that is not connected to a computer, and files that are stored on a computer that is not connected to or not on a network or the Internet.
offline address book (OAB): A collection of address lists that are stored in a format that a client can save and use locally.
offline address book (OAB) data file: A file that contains offline address book (OAB) version 4–specific data, as described in [MS-OXOAB].
offline address list (OAL): A portion of data that is in an offline address book (OAB) and is related to a single address list.
OLE DB: A set of interfaces that are based on the Component Object Model (COM) programming model and expose data from a variety of sources. These interfaces support the amount of Database Management System (DBMS) functionality that is appropriate for a data store and they enable a data store to share data.
OOF message: A message that is sent in response to incoming messages and indicates that the user is currently Out of Office (OOF).
opaque-signed message: An Internet email message that is in the format described by [RFC5751] and uses the SignedData CMS content type described in [RFC3852], or the Message object that represents such a message.
optional attendee: An attendee of an event whom the organizer lists as an optional participant.
Organization object: An Address Book object that describes an entire organization.
organizer: The owner or creator of a conference or event.
orphan instance: An instance of an event that is in a recurring series and is in a Calendar folder without the recurring series. For all practical purposes, this is a single instance.
Out of Office (OOF): One of the possible values for the free/busy status on an appointment. It indicates that the user will not be in the office during the appointment.
Out of Office rule: A rule that is only evaluated when the mailbox is in an Out of Office state.
Outbox folder: A special folder that contains Message objects that are submitted to be sent.