I'm having trouble finding what means the / between two skill listed in a profile. This is an example Military Orders ────────────────────────────────────────────────── 1 CRUSADER Combi Rifle / Pistol, Knife. (0 | 26) 0 SWC | 26 Points Open in Infinity Army AD: Combat Jump / Zero-G
Dash means "or". Crusaders get to choose between Airborne Deployment or Zero-G during deployment phase. (Ignore the / between Combi Rifle and Pistol, that's just an artefact of forum pasting and separates melee weapons from ranged weapons)
It means you have to choose which skill this particular trooper has. In this case, a Crusader can either have AD:Combat Jump, or terrain skill Zero-G, adn be able to traverse Zero-G difficult terrain with no penalties. Edit: oops, too slow =)
It's also present for ammo on some weapons, like the SMG. You get to choose which one you want for that order, but you don't get both.