Is Slagwurm Armor legal in Standard, Modern, and Commander?

Slagwurm Armor is legal in: Modern, Legacy, Vintage, Commander, Pauper.

What type of card is Slagwurm Armor?

Slagwurm Armor is an Artifact — Equipment. Its oracle text reads: "Equipped creature gets +0/+6. Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)"

Slagwurm Armor

Artifact — Equipment

Equipped creature gets +0/+6.

Equip (: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)