This part of ISO/TS 17575 defines the format and semantic of the data exchange between a Front End (OBE plus optional proxy) and corresponding Back Ends in autonomous toll regimes. This part of ISO/TS 17575 deals with the definition of the data elements used to report charging details from the Front End to the Back End and to receive data which can be used to re-configure the ongoing process of gathering charge relevant information in the Front End.