Whether or not some crew are listed under a special edition, restoration or unit header does not really matter to me. It all depends if their role in making the movie was significant and if they may be listed according to the rules. And since the rules say nothing about using dividers for crew, nor do they say anything about sound mixers or art directors inside a unit, I assume they are allowed.

Alright, this popped up again with a recent submission. I checked the credits and there's a sound mixer, make-up artists and art directors included under the 2nd Unit - U.K., 3rd Unit - U.K. and Chicago Unit, so I assume these are still out?

Edit: nm, read the post above. Although it would be nice if the rules reflected this...