>> 
>>>    You have num:2, so subsubsections are not TOC'ed, so they don't get
>>>    the alternative. If you set it to 3, all should work.
>>> 
>>> That is what we have been discussing. There are situations where you
>>> do not want a headline to appear in TOC, but still want the ALT_TITLE
>>> used. It is now possible in org-mode, but there was some bug because
>>> of which it did not always work.
>>> 
>> 
>> I figured I was missing something, but I have a question (which means
>> I'm still missing something :-) : what are ALT_TITLEs good for if not
>> for the TOC?
> 
> I think some styles put them in the header, regardless of TOC.


Also needed if you need to add a footnote to a section heading.

Vikas