Flingwing207 is correct, although I would argue with the "world famous" part..
It is a huge and complex subject to try and cover in 5 minutes I agree and not a task to be taken lightly if to do it justice! I'm now considering focusing on a particular operation within this category type. Although finding reference material is proofing difficult. My brief is simply; Restricted and Experimental Category Helicopters - What can you use them for?