I went to MSOE after growing up in Southern California. Bubbler was a key way to identify those from Milwaukee and immediate surroundings. It's such a precise locator; even more so than calling I-5 the 5, just as accurate, but the 5 gets you to like Santa Barbara and south, where bubbler cuts off just over the Milwaukee county line. A Racine native drinks from a fountain like everyone else; Brookfield natives might use a bubbler.