Might be some kind of Grammar school or Middle school classification. Then again this looks like a very local thing, but who knows. Maybe you need to contact the people and ask what that means.
After further review and looking at the clinicians and the draw to the camp, this must mean college. Then again, that is not a good way to give information for your camp in my opinion. Most camp brochures spell out the levels and not use acronyms.
Peace