This part of ISO/IEC 16500 on"Contours: Technology Domain" describes the system functions and DAVIC tools relevant to the Contours defined in ISO/IEC TR 165001. A goal of this part of ISO/IEC 16500 is to guide implementers to those parts of ISO/IEC 16500 which are relevant for the implementation of the systems in each Contour and to show the relation between the various tools. Another goal of this specification is to state which specific DAVIC tools have to be implemented to realize interoperable system components. As the underlying trade-off between system component cost and service revenue may vary considerably, e.g., by geographical location and time, this trade-off is deemed to be outside of the scope of DAVIC and hence a more detailed "micro profiling" of the tool set needs to be agreed upon between the various parties involved with the realization of a system. An STB that is fully interoperable with, for example, Enhanced Broadcast Services within a certain geographical area, can be designed by implementing all defined DAVIC tools used by the Enhanced Broadcast Services in that area. In order to assist the above mentioned micro-profiling activity the DAVIC tools relevant to a specific Contour have been structured in the following way. A collection of DAVIC tools (sub/clauses of ISO/IEC 16500) which together realize a complete system function (e.g., the reliable transmission of synchronized multimedia information) are grouped together. The group is identified as "system function". For each of these groups an overall informative description is given and a table listing in detail the included DAVIC tools. For the tools dependencies are indicated if applicable. The functional requirements derived from the User & Market Domain of a contour (see ISO/IEC TR 16501) are fully mapped to the above list of system functions.