Is Relic Axe legal in Standard, Modern, and Commander?

Relic Axe is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Relic Axe

Q: What type of card is Relic Axe?

Relic Axe is an Artifact — Equipment. Its oracle text reads: "When this Equipment enters, attach it to target creature you control. Equipped creature gets +1/+1. If it's a Warrior, it gets +2/+1 instead. Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)"