On Oct 21, 2013 6:12 PM, "Nicolas Goaziou" <n.goaziou@gmail.com> wrote:
> Optional arguments are in square brackets in LaTeX. Try %r instead, so
> you can write:
>
>   *** {0.9\textwidth}{0.7\textheight}   :B_overlayarea:
>       :PROPERTIES:
>       :BEAMER_env: overlayarea
>       :END:

Ah, OK, that's better.

It's not easy to grasp the correct terminology and structure from the
available documentation. I do appreciate the excellent help from the list
in such cases!

This part of the documentation might benefit from some examples of
generating different types of beamer syntax -- when to use properties, when
to use headline text, etc. I wouldn't have guessed to use the headline text
because I was thinking of parameters or arguments.

> > Also, side note, [1] seems not to document BEAMER_OPT for environments
> > within a frame. Reading this page, you would think you could only use
> > it for frames. I had to dig into the source code to find how to
> > populate %o.
>
> Would you mind suggesting a better phrasing?

Under "Block environments and overlay specifications," where it discusses
custom environments, I would add:

~~
- Environment options may be given using the BEAMER_opt property. They will
be enclosed in square brackets and inserted where %o appears in the
environment definition.
(with an example, but I can't think of one now)

- Additional arguments may be written into the environment's headline, and
inserted into the LaTeX string using %r (raw headline text, no processing).
~~

I think it's important to mention it in the section where it can be used.
My faulty conclusion was based on the fact that the only mention of _opt is
in a section about frames.

hjh
hjh