Is Dueling Rapier legal in Standard, Modern, and Commander?

Dueling Rapier is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Dueling Rapier

Q: What type of card is Dueling Rapier?

Dueling Rapier is an Artifact — Equipment. Its oracle text reads: "Flash When this Equipment enters, attach it to target creature you control. Equipped creature gets +2/+0. Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)"