Define the unique technical identifier of the interface.

Specify the version of the interface that is described by this document.

Define the type of the interface which may be internal (used by components of the system you design) or external (also used by components outside the system you design).

The value is edited by the use of the Interface Type Macro.

The level is relevant if you want to document an interface by individual parts.

Add references to information on external systems here.  This is useful if the documentation for an interface is defined elsewhere or may be provided by the interface on-demand.