ISO/IEC 13522 specifies the coded representation of multimedia/hypermedia information objects (MHEG objects) for interchange as final form units within or across services and applications, by any means of interchange including local area networks, wide area telecommunication or broadcast networks, storage media, etc.

MHEG objects are usually produced by computer tools taking as a source form multimedia applications designed using multimedia scripting languages. In this context, one of the MHEG object classes, the script class, is intended to complement the other MHEG classes in expressing the functionality commonly supported by scripting languages. Script objects express more powerful control mechanisms and describe more complex relationships among MHEG objects than can be expressed by MHEG action and link objects alone. Furthermore, script objects express access and interaction with external services provided by the run-time environment.

Other parts of ISO/IEC 13522 define the coded representation for script objects in an open manner so that script objects may encapsulate either standardised or proprietary script code. Script objects encapsulate scripts that may be encoded in any encoding format as registered according to ISO/IEC 13522-4.

The scope of this part of ISO/IEC 13522 is to extend the coded representation of the MHEG script object class defined by another part of ISO/IEC 13522, including ISO/IEC 13522-1 and ISO/IEC 13522-5.

This part of ISO/IEC 13522 specifies the MHEG script interchange representation (MHEG-SIR) for the contents of script objects, i.e. the encoding of the script data component of the MHEG script class.

MHEG engines are system or application components that handle, interpret and present MHEG objects. This part of ISO/IEC 13522 also specifies the semantics of interchanged scripts. These semantics are defined in terms of minimum requirements on the behaviour of MHEG engines that support the interpretation of interchanged scripts.

This part of ISO/IEC 13522 is applicable to all applications that interchange multimedia and hypermedia information.