[O] How to allow for no-date when prompting for a DEADLINE?

[Sebastien Vauban]

Hello,

I would like my TODO capture template to prompt me for a due date, as this is
often an "intrinsic" property of the task (fill your tax report, answer for
presence at birthday party, etc.).

However, some tasks don't have or don't need a due date. But the prompt does
not allow me to answer "none":

#+begin_src emacs-lisp
          (setq org-capture-templates
                `(("t" "Task" entry
                   (file+headline ,org-default-notes-file "Tasks")
                   "* NEW %^{Task Name}%? %^g
  DEADLINE: %^{Due Date?|}t
  :PROPERTIES:
  :Effort: %^{Time Estimate|0|10|30|60|120}
  :END:

%i"
                   :empty-lines 1)))
#+end_src

You can see, here above, that I tried to change the prompt label, and to
include an empty default value, but that does not make it...

In fact, it is a bit worse than that: I'd like no DEADLINE line to be inserted
in this case.

Maybe the way I try to solve my problem is getting too complex. Any idea?

Best regards,
  Seb

-- 
Sebastien Vauban