CSO, ship via

Hello, few question here about create a CSO 3 order. I think this apply to canada only but when you go on global and create a order CSO, i have: SIC* . I can chose 1 or 0 or blank. Same thing with: Ship via WC or CUR or blank. i have done my CSO leaving these two with a blank. I think it works. Can someone tell me this option are for? Thanks