Unusual Lisp application

Here in New Haven, Connecticut, a single company seems to have a monopoly on parking. What's remarkable are their signs, which point to a clear influence of Lisp technology on operations. Here is a particularly fine example:


Granted, the angle-bracket prompt is out of place, and it is perhaps poor practice to give a name like (p) to such a crucial function, but in all likelihood these are mere tactics to avoid revealing trade secrets to competitors.