In Clojure 1.4 what is the use of refer within require?

Question

What advantage does using :refer in :require have over using :only in :use? Are the following synonymous?

Answer 1

Main idea of adding :refer to :require is to get rid completely of :use, leaving only one operator to load other packages. You can emulate existing :use with (:require [my.lib :refer :all])...