This Recommendation describes the elements of signalling information used by the Bearer Independent Call Control protocol and the ISDN user part and their functions. The encoding of these elements, the format of the messages in which they are conveyed, their applicability to the two protocols, and an indication of whether or not they are for national use, are described in ITU-T Rec. 4.1902.3. Throughout this Recommendation where a message, a parameter or parameter information relates to either physical circuits controlled by the ISDN user part or the BICC protocol call instances the notation "circuit/CIC" is used. Also, a generic term %ode" is used to refer to signalling entities in either the ISUP (Le. an exchange) or the BICC network (i.e. either an SN or an CMN) whenever a message, a parameter or parameter information is applicable to either.