I think it was called the line? Me and my school friends used to call it from phone boxes or a landline when at one of our homes and talk to the staff for ages trying to prankcall them or asking them stupid questions. It was just a phone line you could ask anything to. I guess because we didn’t have the internet at our fingertips as easily then. This was probably about 2007/08. I’ve tried Googling, just out of interest but of course nothing comes up as the search terms are so vague.