Call Waiting Deluxe is the Bellcore (now Telcordia Technologies

Telcordia Technologies

Telcordia Technologies, formerly Bell Communications Research, Inc. or Bellcore, is a telecommunications research and development company based in the United States created as part of the 1982 Modification of Final Judgment that broke up American Telephone & Telegraph...

) term for Type II caller ID

Caller ID

Caller ID , also called calling line identification or calling number identification or Calling Line Identification Presentation , is a telephone service, available in analog and digital phone systems and most Voice over Internet Protocol applications, that transmits a caller's number to...

 with Disposition Options.

This CLASS-based POTS

Plain old telephone service

Plain old telephone service is the voice-grade telephone service that remains the basic form of residential and small business service connection to the telephone network in many parts of the world....

-telephone calling feature works by combining the services of call waiting

Call waiting

Call waiting , in telephony, is a feature on some telephone networks. If a calling party places a call to a called party which is otherwise engaged, and the called party has the call waiting feature enabled, the called party is able to suspend the current telephone call and switch to the new...

 with caller ID

Caller ID

Caller ID , also called calling line identification or calling number identification or Calling Line Identification Presentation , is a telephone service, available in analog and digital phone systems and most Voice over Internet Protocol applications, that transmits a caller's number to...

 but also introduces an "options" feature that, in conjunction with certain screen-based telephones, or other capable equipment, gives a telephone user the option to

• Switch: Place the current call on hold to take the second call (not a new feature)
• Hang-up: Disconnect the current call and take the second call
• Please Hold: Send the caller either a custom or telephone-company-generated voice message asking the caller to hold
• Forward to Voice Mail: Send the incoming caller to the recipient’s voice mail service.
• Join: Add the incoming caller to the existing conversation.

For more information, please see the Analog Display Services Interface

Analog Display Services Interface

Analog Display Services Interface is a telephony technology that is currently used in POTS or computer-based PBX telephone service. It works in conjunction with a screen-based telephone or other compatible CPE to provide the user with softkey access to telephone company or internal PBX custom...

article.