(defun org-add-note-mark ()
    (interactive)
    (defvar title ())
    (setq title(org-entry-get nil "ITEM")) ; Get the current title
    (if (string-match-p "|N|" title) ; If there is a Mark already
        (org-add-log-setup 'note)    ; Go to take a note
      (setq newtitle(concat title " |N|")) ; If not, add it
      (org-edit-headline newtitle) ; Write it
      (org-add-log-setup 'note))) ; and go to take a note
(define-key org-mode-map (kbd "C-c C-z") 'org-add-note-mark)