Is Strength of Unity legal in Standard, Modern, and Commander?

Strength of Unity is legal in: Legacy, Vintage, Commander, Pauper.

Strength of Unity

Q: What type of card is Strength of Unity?

Strength of Unity is an Enchantment — Aura. Its oracle text reads: "Enchant creature Domain — Enchanted creature gets +1/+1 for each basic land type among lands you control. *All Dominarians agreed on one thing: they would not go down without a fight.*"