Armor abilities in Custom Match?

I have been trying to figure out how to activate the use of the armor abilities in Halo: Reach custom game Multiplayer. Is there some kind of trick to it or are there only certain maps that they can be used in? Please help I know this is a newbie question.

Go to “Spartan Loadout”, the go to “Tier 1” then “Loadout 1” and choose the ability you want. There’s also an option there at the bottom and by default it’s set to “hidden”. For the loadout to work, you need to switch it to “not hidden”.