In fact, in about 1971 there was a sudden spate of development in this area, and both the University Library and what was then Brighton Public Library and West Sussex all  were innovators in those days, using computer-based lending systems, which used little cards with lots of little holes in them and — I am sure they are familiar to lots of people — in the last few years you'll have seen those holes replaced by sort of zebra stripes erm what are called bar codes in the trade, and those bar codes you'll also see on your groceries all over the place.