https://en.wikipedia.org/wiki/PEnnsylvania_6-5000
PEnnsylvania 6-5000 is a telephone number in New York City, written in the 2L+5N (two letters, five numbers) format that was common in the largest US cities from approximately 1930 into the 1960s. The named Pennsylvania exchange served the area around Penn Station in New York. The two letters, PE, stand for the numbers 7 and 3, making the phone number 736-5000, not including the later area code 212 for Manhattan.