Why does the separator "::" work with headlines?
>
It doesn't seem to have any effect for me, it gets handled as part of the
headline, both in fontification and in exports:

[image: image.png]
[image: image.png]

Which is, as I understand it, as it should be, since it doesn't have any
special meaning in headlines.

In your case it seems indeed to be getting fontified as if it were a list.
What version of Org do you have? I am using 9.5 on Emacs 27.2.

--Diego