Can you provide a list of all the characters needed for Chinese typesetting?
There is a sidebar entry for Chinese. Is that what you are looking for?
Chinese vertical writing may involve the use of some special control characters, and this is what I mean.
Those are not relevant for the font design and so we usually don’t deal with this topics. So I can’t help you with the information.
Yes, they are empty glyphs and have nothing to do with the production process.