Wrap a function definition with `deprecated' to indicate that it should no longer be used. If the first element of body is a string, it will be used as additional documentation in the deprecation message. Foo example, (deprecated “Use bar instead.” (defun foo-1 (x) (format t “~%FOO: ~A” x))) Will generate the message: ; warning FOO-1 has been deprecated. Use bar instead. at compile time whereever foo-1 is used.