FAQ

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 73-3317 not including the later area code 212 for Manhattan.

It is also a reference to Glenn Miller's Pennsylvania 6-5000 song. In the movie, it shows Melanie dialing Jack's number and it is: 736-3317. The 7 and 3 being a reference to Penn Station, the 6 from the song, and then his last four digits 3317.