This part of ISO 22900 defines an object-oriented programming interface, the objective of which is to be able to implement server applications used during the design, production and maintenance phase of a vehicle communication system which are compatible with each other and therefore exchangeable.

A server compliant with this part of ISO 22900 has three function blocks: - M: measurement, - C: calibration, and - D: diagnostics. A more detailed description of the server API is given in the Programmers Reference Guide[14].