scope:

This European Telecommunication Standard (ETS) specifies rules for the use of the Specification and Description Language (SDL), defined in ITU-T Recommendation Z.100 [1] and Message Sequence Charts (MSC), defined in ITU-T Recommendation Z.120 [3], in ETSs. Object oriented extensions in SDL are not considered. It is intended that SDL and MSC diagrams will be used in ETSs, in combination with text, informal figures and tabels. SDL diagrams are to be used to formalise those parts of an ETS that need to be defined precisely and unambiguously.