Silent_number
Unlisted number
Telephone number that is unpublished
In telephony, an unlisted number (United States, New Zealand), ex-directory number (United Kingdom) silent number, silent line (Australia[1]), or private number (New Zealand, and Canada) is a telephone number that, for a fee,[2] is intentionally not listed in telephone books. Although an unpublished number is not included in the phone book, an unlisted number may be available from the phone company's information operator.[3] When used for residential households, they're primarily for privacy concerns.[4]
Another form of anonymity is being listed with just a first initial, for those with a relatively common family name; sometimes these listings also lack an address. No fee is charged for initially being so-listed.[5][6][7]