The purpose of this Recommendation is to provide the stage 1 description of the method defined in Recommendation I.130 using the means given in Recommendation I.210.Supplementary services are described by a prose definition and description (step 1.1) and by a dynamic description (step 1.3).The application of the attribute technique (step 1.2),as defined in Recommendation I.140,for supplementary services is for further study.