Who gets to decide how we should misspell a word?

Here in Boston, natives have a unique accent. Locals have adopted it to give unique names to their businesses. Just down the street, we have a little variety and curio shop with the creative name, “Whaddya Need”. Walk a few blocks from that and you come to a convenience store called Connah Store. I’m not sure why it isn’t Connah Stoah, but it is what it is.

Damon Runyon was an author with a great gift for phonology. He could concoct phonetic spellings to bring alive for his readers the strong accents common to a protagonist from Brooklyn or Manhattan in New York.

Is any misspelling that gets the idea across OK, or are there rules of phonetics that makes one phonologist’s interpretation better than any other?