Alright, this is one that a couple of people have done for other programs that use an upwards Y-axis (Maya, SoftImage etc.), but this works for an upwards Z-axis for programs such as 3ds max, Blender etc.
The extra feature this offers is that it prevents camera rotations from flipping over, eg, instead of going from 359 to 1, it will now go from 359 to 361. This makes a significant difference if you plan on using the camera for motion blur, as otherwise you will get a frame of extreme rotational blur. So, that’s what it does, let’s see how it works.