Re: `\paper`-only variables

[Werner LEMBERG]

>> Do we have a list of variables that only have an effect if set in
>> `\paper` (and not in `\layout`)?
> 
> What do you want this for?

I'm working on issue
https://gitlab.com/lilypond/lilypond/-/issues/1392 (but not for the IR
but as an appendix for the NR) and I would like to avoid writing the
sentence

  `foo` may also be specified in `\layout` blocks

again and again.  I could imagine that the opposite, namely

  `foo` has no effect if added to a `\layout` block

would be better.


    Werner