You might check out my scimax-editmarks package. You can create bracket syntax like that which can be fontified, e.g. made smaller, lighter, etc. to de-emphasize. It is not org-syntax, and uses a pre-processing step on export, but if all you want is visual syntax in org-mode, something like this might be what you are looking for. The details are in this video description, and you can see what it looks like and does here https://www.youtube.com/watch?v=qBmvBkpzixs

John

-----------------------------------
Professor John Kitchin (he/him/his)
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803


On Thu, Jan 13, 2022 at 2:16 PM fatiparty--- via General discussions about Org-mode. <emacs-orgmode@gnu.org> wrote:

Jan 14, 2022, 06:50 by maciaschain@posteo.net:

> Hi,
>
> fatiparty--- via "General discussions about Org-mode." writes:
>
>> Is there anything to perform the opposite, playing down the text?
>>
>
> Are you referring to nested emphasis, something like in LaTeX
>
> \emph{foo \emph{bar} baz}
>
> = foo...baz in italic; bar in normal font?
>
> Best regards,
> Juan Manuel
>

I am referring to an org file.  Suppose I have a file doc.org

cat doc.org

a  celebration that started in the 4th Century [IV] in the Southern Levant
 [ _a geographical region that corresponds to present-day Israel and Palestine_ ].

org-mode in emacs will emphasize by underlining geographical detail.  I would like 
to have a way to play down the text rather than emphasizing the text.  It would be
beneficial to have other bracketing characters for doing the opposite of emphasizing.