The black list? You call them up (phone nr listed on their site somewhere) and ask to be transferred to it, they send you a letter to sign, you send it back, you are then removed from
www.directories.ch. It means no one, not even in emergencies will be able to get your number using their database. The problem is, once the database has been sold, that is it, too late.
I know that
http://tel.search.ch/index.en.html have probably bought the national database, as we are still listed in theirs, so they must have gotten the data of Swisscom or whoever stores these things...