-If N is negative, print the N previous articles. If N is nil and articles
-have been marked with the process mark, print these instead.
+If used interactively, print the current article if none are
+process-marked. With prefix arg, prompt the user for the name of the
+file to save in.
+
+When used from Lisp, accept two optional args FILENAME and N. N means
+to print the next N articles. If N is negative, print the N previous
+articles. If N is nil and articles have been marked with the process
+mark, print these instead.