Thanks for the explanation. To place "A" etc in a more exact context, Denver has the same confusion. Columbine High School is not in Littleton, CO. It is located in unincorporated Jefferson County. Littleton, CO is in Arapahoe County. With its own school district. Two different counties, school districts and even different congressional districts. But the area around Columbine is assigned to the Littleton Post Office and its ZIP code is part of the Littleton P.O. numbering system. I doubt, given the difference in counties, that there will be the confusion of your A, B and C. But the citizens of Littleton -- especially those in employed and attending Littleton Public Schools, darn well wish that Columbine had been assigned to someone else's post office! Take care, Bob JUDY AND BOB HUDDLESTON 10643 Sperry Street Northglenn, CO 80234-3612 303-451-6376 [log in to unmask]