[O] BEAMER_act property documented in ox-beamer.el

[Sebastien Vauban]

Hello,

I'm trying to understand the sentence from ox-beamer.el:

    Headlines also support the "BEAMER_act" property.  [It] is translated as an
    overlay/action specification (or a default overlay specification when
    enclosed within square brackets).

Rewritten, it says that that property is translated as:

- a default overlay specification *when enclosed within square brackets*, or
- an overlay/action specification *when NOT enclosed within square brackets*.

Though, I don't understand exactly what that *default* specification really
means. Moreover, I can't get it: without square brackets, PDFLaTeX becomes
crazy...

--8<---------------cut here---------------start------------->8---
* Overlay/action specification enclosed within square brackets

The following 2 cases are exported in exactly the same LaTeX code.

** With angular brackets
   :PROPERTIES:
   :BEAMER_act: [<+->]
   :END:

- Item 1
- Item 2

** Without angular brackets
   :PROPERTIES:
   :BEAMER_act: [+-]
   :END:

- Item 1
- Item 2

* Overlay/action specification NOT enclosed within square brackets   :noexport:

The follow 2 cases make PDFLaTeX infloop...

** Without angular brackets
   :PROPERTIES:
   :BEAMER_act: <+->
   :END:

- Item 1
- Item 2

** Without angular brackets
   :PROPERTIES:
   :BEAMER_act: +-
   :END:

- Item 1
- Item 2
--8<---------------cut here---------------end--------------->8---

Anyone undestanding more than I am?

Best regards,
  Seb

-- 
Sebastien Vauban