Tenon Profile for Type C jaws

What is the recommended tenon profile for use with Type C jaws?
Or should they only be used with the worm screw plate?

Having completed a course with Axminster, the recommended length of the tenon was approximately 7mm deep. As long as the work does not butt up against the chuck it should be OK. 66mm to 80mm diameter for a compression mode fitting. There is a small tooth which will aid gripping therefore (in my opinion) there is no need to dovetail the tenon as the tooth will bit into the work, however a low angle one as cut with a standard grind skew does no harm.
A perfect circle is formed when the carriers line up with the outside of the chuck body. This is for the SK100 and 114 and I would imaging the same is correct for the SK80. They may be used with the screw plate or without. Full information is available on their website.