Tuning a catamaran rig

[Robbie.g]

This was just an out-of-interest-question.. Saw a rigger on a boat, (cat) ,. 40ft long.triple spreader, forward jumpers near the masthead. Caps/'backs' 10 ft ish aft of the mast, lowers 5 ft ish aft of the mast. Just wondered how tuning a cat rig differed. Understand,. in a 'farmers' sense how to get the mast in column, but getting pre-bend needed a 'font of knowledge' to explain, in my small brain.
Thank you for satisfieing my curiosity.