I haven't yet found a good answer. Or any answer, for that matter. I've been asked to teach a discrete structures for CS course, but at the same time make sure it's not a discrete mathematics course -- that's offered by the Mathematics department.
Many colleges offer a discrete structures course. There are also many DS textbooks. But when I look at the course syllabi and the textbook introductions, the term "discrete structures" is never used; they use "discrete mathematics" instead. DS only appears in the title of the course/textbook.
Examples:
Discrete Structures entry at Wikipedia
What's discrete structures and how does it differ from discrete mathematics?
I have http://www.amazon.com/Discrete-Computational-Structures-Computer-Mathematics/dp/0124208509 which seems to be what they're asking for.
Chapter 1 says "This is a book about structures."
Always, since our interest is in digital computation, our structures will be discrete.
I supposed you could split that hair and say "see, it's just discrete mathematics warmed over." While it might be true, I think it's only a matter of focus.
It becomes discrete structures when the focus is on digital computation.