No, most warehouse style stores will not trigger department store coding.
Most department stores will be similar to Macy's, JC Penny, Sears, etc. The kind of store you'd expect to find as an anchor store in a mall with multiple departments of widely varying types of merchandise.
I just found this posted from another forum. I really couldn't find anything on Discover's site, but I didn't really hunt. This list is consistent with my own experience.