Nicolas Goaziou <mail@nicolasgoaziou.fr> wrote:
> Dmitry Alexandrov <321942@gmail.com> writes:
>
>> Now, I am not sure, whether am I supposed to use #+begin_org-center
>> blocks instead of #+begin_center too.
>
> The latter. As I explained, ".org-center" is an internal style.
>
>> In fact, given that #+begin_center creates a .org-center div block,
>> that is centred by default CSS (and stylesheets of other formats),
>> I found your answer absolutely surprising.
>
> "Center" blocks are defined in the manual, along with their syntax.

Thank you, I will.

> There is nothing surprising.
>
> Moreover, there is no such thing as a "Right" block. Or, more precisely,
> this falls into the special block category, which is handled differently
> in each export back-end.
>
>> I would be probably not alone on this feeling; see, for instance,
>> Fabrice Niessen’s Org mode syntax reference card [0], where (as far as
>> I got it) #+begin_right is presented as alignment tag for paragraphs
>> rather than tables:
>
> This reference card is not an official reference card.

Yes, I fully realize that.

Just another unofficial reference card [0], by Caio Rordrigues at that time, that again states that:

--8<---------------cut here---------------start------------->8---
#+begin_right
This text is
aligned to the right!
#+end_right
--8<---------------cut here---------------end--------------->8---

These persons are probably consider themselves highly familiar with Org, yet they have been mistaken.  What to say about novices!  So the absence of this feature is indeed highly unobvious.  That’s the only point I am trying to make.

[0] https://github.com/caiorss/Emacs-Elisp-Programming/blob/master/Org-Mode.org#text-position

> In any case, let me insist again on the following point: you can use
> "#+begin_right" in HTML to your heart's content if you define the
> appropriate CSS property.

If there is no plan to make into default as with centring, a warning might be very apt.

Thank you again for your work on the Org.