AT Guns considered hard or soft targets

[FroBodine]

Again, I can't find this in the manual.  Are anti-tank guns hard or soft targets?

And, how can I tell from looking at unit cards if any given unit is hard or soft?  I see large armor shows hard target as text on the unit card, but I can't see that on the enemy unit cards.  

Thanks again from a newbie trying to figure the details out.

-=Jeff