ISO/TS 21308-4:2007 describes the mapping to STEP application protocol 239 for the exchange of dimensional data between truck chassis manufacturers and bodywork manufacturers. It applies to commercial vehicles, as defined in ISO 3833, which have a maximum gross vehicle mass greater than 3 500 kg.

The process of exchanging the above information can involve

• the chassis manufacturer,
• the chassis importer,
• the chassis dealer,
• one or more bodywork manufacturers, and
• bodywork component suppliers, e.g. manufacturers of demountable bodies, cranes and loading equipment, tipping equipment.