The header should still be highlighted in some way if present I suppose?

Yeah, you probably just want to add a rule default("script") at the end of the root state.

@birkenfeld unfortunately as there is no way to find out if the code is a complete script or just a snipped of it, the header may not be highlighted how it was. Because one could have such an input:

switch language [
    Rebol [ print "bla" ]
    Perl  [ print "foo" ]
]

It is currently also broken.

But as the header is just an ordinary Rebol data, it will be highlighted too... the only difference is, that what is before header in a complete script will not be handled like a comment.

OK, makes sense. Just one nit: please remove the unneeded code instead of commenting.

@birkenfeld the code is removed now.

Thanks!