Are folders of content not allowed to be added to requests?

Users would like to attach folders of content to requests they submit to our team, but the folders don't seem to be attaching. Through testing I've experienced the folders not attaching to the requests, but if I try the pieces of content they attach successfully regardless of the file type and amount of content I try so far. That leads me to believe that folders of content can't be attached to requests, is that correct?