Hiding Units on minimap

I want to have units exist in the map but not show up in the minimap, mainly these are buildings and I dont want people to see them they are hidden units.

one question, do these units have to be targetable, and do they have to be destroyable?

if your answer is no to both of those, then simply give them the Unknown(Aloc) ability

That worked, thanks

Np, thats what i'm here for :P