Hi all, This happened to me a couple times where I have a form like this (with-html (:html (:body (str (get-error-messages))))) Now if there's no error, (get-error-messages) returns NIL, otherwise it returns a description of the problem. This function also serve as a predicate for other code. But (str (get-error-messages)) actually prints a "NIL" to the browser. Of course I could replace (str (get-error-messages)) with (let ((messages (get-error-messages)) (when messages (str messages)))) or (str (or (get-error-messages) "")) however it's getting rather verbose. But the real issue is that the string "NIL" really doesn't make sense in HTML, XML or JSON. It's only something that a Lisp programmer would understand. So I'm purposing to change the substitution of (str form) => (princ form1 s) to (str form) => (let ((#:result form1)) (when #:result (princ #:result s))) Attached is a diff for this change in case you guys agree that this makes sense. Thanks, -- Mac