John wrote:


Do they only display names where the number and name has been programmed in
(like with a mobile?) or do they display all numbers?

They display all numbers of the person calling, unless that person has
deliberately withheld their number. I have had a lot of silent calls
to my office but not to my home which is ex-directory, they do indeed
display the number calling, this information is also logged, so that
information can be used later if these are malicious calls and are
admissable in litigation.