Is Assault Formation legal in Standard, Modern, and Commander?

Assault Formation is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

What type of card is Assault Formation?

Assault Formation is an Enchantment. Its oracle text reads: "Each creature you control assigns combat damage equal to its toughness rather than its power. {G}: Target creature with defender can attack this turn as though it didn't have defender. {2}{G}: Creatures you control get +0/+1 until end of turn."