This Recommendation is one of a series of Recommendations to enable support for preferential telecommunication services over IPCablecom networks. These specifications do not apply to ordinary emergency calls such as people calling the police@ the fire department@ ambulances@ etc. Aspects of preferential telecommunications include provisions for authentication and priority (special handling). The objective of this Recommendation is to provide an initial set of authentication specifications for preferential telecommunications within IPCablecom2 networks according to the framework described in [ITU-T J.261]. This Recommendation defines specifications for capabilities@ which@ when implemented should help support preferential treatment telecommunication services. NOTE ?C Pre-emption specifications and authorization specifications are outside the scope of this Recommendation and are considered to be national matters.