0 used to refer to a phone number that is not made public by the phone company: --
1 used for describing a telephone number that is not in the public telephone directory (= book that lists numbers) and is not given by the telephone company to people who ask for it: --
I believe that most people would be surprised to find out that registering one's number as ex-directory does not provide protection against calls from direct marketers.
Similarly, some people prefer their telephone numbers to be ex-directory, partly because they are unhappy about their names and addresses appearing in a public document.
There are problems for those who are ex-directory for security and other reasons, but they can have their numbers excluded.
There is no question of her going ex-directory.
Despite the fact that she changed her telephone number and went ex-directory, and changed the number of her workplace telephone, the calls persisted.
People who are ex-directory would already be excluded from such lists, if they were to be sold.
She even went to the additional trouble of going ex-directory, but continued to receive such calls.
Police had to be posted and the victim's telephone made indefinitely ex-directory.
