Hi, Orgxperts

assume I have something like this:

** Some heading
   :properties:
   :foo: some value for foo
   :bar: some value for bar
   :end:

Now, when I do

  (org-element-properties-mapc
    (lambda (k v) (message "%s -> %s" k v))
    (org-element-at-point))

I do see foo and bar (well, OK, :FOO and :BAR) with their values, but lots
of other (let's call them "built-ins") like :begin and :post-affiliated.

How do I keep those apart? Or do I have to resort to running regexps through
the buffer?

Cheers & thanks
-- 
tomás