With commands MLEADER and QLEADER as a replacement for and addition to the LEADER command, there are plenty of ways to draw a leader. But what if you want a leader without annotation? The question sounds silly but it isn't. I've been asked many times in my life.
It turns out there is only one way to do it right - and only one. The command:
LEADER <enter> <select start point> <select end point> <enter> <enter> n <enter>
You can change properties (Ctrl+1) like DIMSCALE, make it annotative and attach an annotation scale, like all other dimensions.
A classical example to learn LISP for BricsCAD or AutoCAD. In LISP it should look something like:
(defun arrow (/ cmdechoorg pt1 pt2)
(setq cmdechoorg (getvar "cmdecho"))
(setq pt1 (getpoint "\nSpecify arrow start point: "))
(setq pt2 (getpoint pt1 "\nSpecify trailing end point: "))
(setvar "cmdecho" 0)
(command "._leader" "_non" pt1 "_non" pt2 "" "" "_none")
(setvar "cmdecho" cmdechoorg))