@mcfate Indeed, there are a lot of places in South Berkeley/North Oakland where you need the mailing address to see which city a house is in -- the whole address, not just the zip code.
But in terms of popular image, even in civic identity, they're pretty far apart. Oakland's industrial, a port town, practical. Berkeley is intellectual, idealistic.
Not really as different as the media paint them, but different enough that no candidate for state or national office will say they're from Berkeley.