;; (setq overlay (make-overlay from to))
;; ;; Put an image.
;; (overlay-put overlay 'before-string icon)
-;; ;; Put a mark that this overlay is made by `wl-e21'. It is not always
-;; ;; necessarily.
+;; ;; Put a mark to indicate that this overlay is made by `wl-e21'.
+;; ;; It is not always necessarily.
;; (overlay-put overlay 'wl-e21-icon t)
;; ;; Make it can be removable.
;; (overlay-put overlay 'evaporate t))