C

canonical form: A conventional and normalized form of any entity, such as an address, phone number, or identifier, that could exist or be presented in several different forms. An entity's canonical form is regarded as the most straightforward of its possible forms and the one that best facilitates interactions with other entities of the same type, particularly comparisons. In MAPI, canonical form is most often applied to e-mail addresses.
CCITT: The International Telegraph and Telephone Consultative Committee, an international standards committee and division of the United Nations that defines standards, such as the Electronic Data Interchange (EDI) data standard. Now called the International Telecommunications Union (ITU). CCITT stands for Comite Consultatif International Telegraphique et Telephonique, the committee's original French name. See also X.400, X.435, X.500.
client: See client application.
client application: A program that enables its user to interact with an underlying messaging system by calling functions or interface methods implemented by the MAPI subsystem or a service provider. These functions and methods are known collectively as the client interface. See also messaging application, service provider interface.
client extension: A program component that adds to the feature set of a client application, for example a handler for custom commands. Client extensions implement the IExchExt : IUnknown interface or one of its sibling interfaces. For more information, see Interfaces for Extending the Microsoft Exchange Client.
client interface: The set of interfaces and functions used by a client application. The client interface has four components: MAPI, Simple MAPI, Common Messaging Calls (CMC), and the Active Messaging Library. The last three components are layers between the client application and the MAPI component, and they make calls to MAPI. The client interface can use one or more of these four components in any combination. For more information, see Selecting a Client Interface.
CMC: See Common Messaging Calls.
common dialog box: A Microsoft Windows dialog box that is provided with the MAPI SDK. A client application uses common dialog boxes to promote an appearance both consistent within the application and consistent with other Windows-based applications. See also dialog box.
common extension set: A predefined set of Common Messaging Calls data extensions. The common extension set includes the extensions most frequently used in messaging systems and in CMC implementations, but which are not in the CMC base specification itself.
Common Messaging Calls: (CMC) A set of functions that is based upon the standard developed by the X.400 Application Programming Interface Association (XAPIA) and that is a component of the MAPI client interface. CMC is a cross-platform function set that enables a client application to be independent of the actual messaging system, operating system, and hardware used. It provides a layer between the client application and the MAPI client interface component. See also Simple MAPI, Active Messaging Library.
Common Messaging Calls data extension: A data structure that is used to add features to Common Messaging Calls (CMC) functions and structures. Data extensions can add members to existing data structures or parameters to existing CMC functions.
compound entry identifier: An entry identifier that is created by combining the entry identifier of a message store and the entry identifier of a message within the store. Compound entry identifiers are used by a client application to open messages from a nondefault message store provider. MAPI, Simple MAPI, and Common Messaging Calls applications can all use compound entry identifiers.
configuration file: A formatted file used to store a user's choices of names, features, limits, and other information that can vary among installations. See also form configuration file, MAPI configuration file.
connection number: A number that uniquely identifies an individual registration for a notification. A client application uses this number to cancel its registration.
container: A MAPI object that holds one or more other MAPI objects. Examples of containers are address book containers, distribution lists, and folders. Containers implement the IMAPIContainer : IMAPIProp interface. See also address book container, distribution list, folder, form container.
contents table: A MAPI table object that provides access to a summary view of entries in a folder or in an address book container. Each row represents a folder, a message, or a recipient, depending on which provider is implementing the table. See also associated contents table, standard contents table.
control: A MAPI object acting as a user interface (UI) for a property. A control appears as an element in a dialog box, where its value can be inspected and possibly changed by the user. For more information, see Display Table Controls.
conversation thread: A series of messages that pertain to the same topic. The topic is held in the PR_CONVERSATION_TOPIC property of each message in the thread. This property and the PR_CONVERSATION_INDEX property facilitate sorting of messages by threads.
custom message: A message with a message class other than those defined by MAPI. A custom message is created and displayed with a special purpose form server rather than with the standard send note or read note form. For more information on message class values, see PR_MESSAGE_CLASS. For more information on custom messages and form servers, see Choosing a Message Class.
custom recipient: See one-off address.
custom recipient entry identifier: See one-off entry identifier.
custom recipient table: See one-off table.
custom recipient template entry identifier: See one-off template entry identifier.