On Wed, Sep 20, 2017, 6:25 AM Nicolas Goaziou <mail@nicolasgoaziou.fr> wrote:
I didn't say it was an unusual case. I said it didn't cover all the
use-cases. Maybe you are really needing a subset of the initial feature.

Understood. 

IOW, do mixed numbered/unnumbered headings make sense in TOC?

Correct. That does not make sense to me. That is not my use case. 

>> 1. it makes all export back-ends consistent with TOC;
>>
>
>  I understand that. But would like a way to get back the earlier behavior
> too.

Then there is the other way around: how do we tell LaTeX to include both
numbered and unnumbered headings?

I see your point. 

AFAICT, this doesn't solve any of the two concerns. What we can do for
"num:nil toc:4" can be done for "num:nil" alone.

That might work.. treat num:nil differently than num:0

So here's the summary as per my understanding.
 
Currently we support these:

1. Don't allow a mix of numbered and unnumbered headings in TOC. If any heading is unnumbered using the UNNUMBERED property, remove it from the TOC. 

2. If we globally unnumber headings beyond a certain level by doing something like num:3, don't show headings beyond that level in the TOC. So num:0 wouldn't number any heading and also not generate the TOC. 

Now the 3rd use case (mine):

3. Unnumber all headings, but still keep them in TOC. 

So allow this 3rd use case when, may be, we have num:nil and not num:0?

WDYT? 

@Carsten: Does this satisfy your use case too?
--

Kaushal Modi