Is Sigil of Distinction legal in Standard, Modern, and Commander?

Sigil of Distinction is legal in: Modern, Legacy, Vintage, Commander.

Sigil of Distinction

Q: What type of card is Sigil of Distinction?

Sigil of Distinction is an Artifact — Equipment. Its oracle text reads: "This Equipment enters with X charge counters on it. Equipped creature gets +1/+1 for each charge counter on this Equipment. Equip—Remove a charge counter from this Equipment."