[Orgmode] LaTeX export of section links

[Francesco Pizzolante]

Hi,

I have a few questions about links to sections.

I've read that it is better to user IDs and CUSTOM_IDs to links to section...

Here's a small example with 4 cases:

--8<---------------cut here---------------start------------->8---
* First
  :PROPERTIES:
  :CUSTOM_ID: heading-a
  :END:

  Hello Toto!

* Second
# <<heading-b>>

  Hello Tata!

* Third
#+CUSTOM_ID: heading-c

  Hello Titi!

* Fourth
#+ID: heading-d

  Hello Tete!

[[heading-a]]
[[heading-b]]
[[heading-c]]
[[heading-d]]
--8<---------------cut here---------------end--------------->8---

Which give the following LaTeX code:

--8<---------------cut here---------------start------------->8---
\section{First}
\label{sec-1}
\label{heading-a}


  Hello Toto!

\section{Second}
\label{sec-2}
\label{heading-b}


  Hello Tata!

\section{Third}
\label{sec-3}


  Hello Titi!

\section{Fourth}
\label{sec-4}


  Hello Tete!

\hyperref[sec-1]{heading-a}
\hyperref[sec-2]{heading-b}
\hyperref[sec-3]{heading-c}
\hyperref[sec-4]{heading-d}
--8<---------------cut here---------------end--------------->8---

The first and second cases both generate labels which are not used in LaTeX.

The third and fourth cases are very elegant as they use only aliases (which
are dropped from the LaTeX code).

My questions are:

- what's the difference between using ID and CUSTOM_ID?

- the cases "Third" and "Fourth" are the more elegant from my point of view.
  Is this the right way of doing?

- what's the difference between cases "First" and "Second" (I mean between
  using PROPERTIES and # <<X>>)?

- in the documentation (section 4.2), we talk about "CUSTOM_ID property" does
  it mean that we should use it as in case 1?

Thanks.
Francesco