I have no relationship with “jawn”, but reading through this article clarified a bunch of linguistic things that I knew but didn’t know how to categorize. The entire read is worth it for the very brief discussion of the word “belt”, but there’s a mountain of linguistic awesomeness here.
http://www.atlasobscura.com/articles/the-enduring-mystery-of-jawn-philadelphias-allpurpose-noun
A Pun Involving Travel 