I'd be very interested in a version of this for Canadian postal code, which have the form K1A 0B1, alternating letters and digits. The first letter is either a province or 1/2 territories, or for Ontario and Quebec is a portion of the province or a metro area. (Vancouver could reasonably be offended at not getting its own first letter.)

Santa Claus's postal code H0H 0H0 would be read as being in the Montreal area (starting with an H), but being rural (second character is a 0). H0 is an almost completely empty prefix, except for an indigenous reserve.