ABSTRACT: GR-520 replaces TR-TSY-000520, Issue 2, but contains NO TECHNICAL CHANGES from that original document. It has been issued strictly to conform with the new Telcordia Technologies document format and GR process, and carries a new issue number and date.

This Generic Requirements (GR) document contains the view of Telcordia on generic requirements for the following features common to residence and business customers:

• Feature Interaction Summary provides a summary of the interaction between pairs of customer features and refers to the specific document for a detailed description of the interaction
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• Four- and Eight-Party Line provides basic telephone service for up to four or eight customers sharing the same line. The feature requires that the system provide fully selective ringing or semiselective ringing with the 4-party service, and semiselective ringing with the 8-party service to customers. The feature also requires a means for any party to call any other party on the same line
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• Basic Business Group (BBG) provides the basic capabilities for handling a group of lines associated with a single customer. BBG includes provision for special dialing arrangements, special restriction arrangements, special alerting capability, and special announcement capability. BBG also provides the capability for the switch to recognize the association of the customer's lines as a group.
• Distinctive Ringing/Call Waiting (DRCW) is one of a collection of signaling features customized for use in a local area, also known as CLASS features. DRCW is an incoming call management feature that allows the customer to designate special telephone numbers so that calls from those numbers may be identified using distinctive alerting treatment.