There's also some social signaling here, like 415 is the original San Francisco area code – but if you got a number in the last few years it might be 628 which was added as 415 reached capacity.
> The episode also featured the New York area code 646. When the 212 area code ran out of numbers, 646 was created. Elaine gets a new number with the 646 area code. She is not happy with the new number because she believes the area code makes it too long to dial. She is proved correct when attempting to give her number to a man in the park. Initially eager, he reads the number, asks if it is in New Jersey. Her response is, "No, it's just like 212 except they multiplied every number by 3…and added 1 to the middle number." He says he is already in a relationship and walks off.