scope:

This document provides a formal means to achieve consistency in the use of ASN.1 when specifying data types that are to be used in ITS International Standards. This is designed to ensure unambiguous and interoperable data exchange while providing consistent documentation of these exchanges. This document provides the necessary specifications to ensure consistent interpretation by providing formal references to several standards and in some cases specifying additional rules to promote greater consistency among standards.

This document does not require the use of ASN.1 for anything other than providing data type definitions in a common and flexible form. This document makes specific provision for the support of:

- Embedding other extant standardised encoding formats, e.g. jpg, while maintaining interoperability and reuse within ITS;

- Allowing alternative representations of data type definitions, e.g. XML schema;

- Allowing alternative encoding of defined data.

The rules presented in this document enable data types to be recorded in a common ITS data registry, and in ITS International Standards, in a common and consistent form.