What are the allowed characters in a Clojure keyword?

Question

I am looking for a list of the allowed characters in a clojure keyword. Specifically I am interested to know if any of the following characters are allowed: -

Answer 1

starting in 1.3 you can use ' anywhere not starting a keyword. so :arthur's-keyword is allowed now :)

I use the keywords :-P and :-D to spice up my code occasionally (as synonyms for true and false)