In August, Halsey took to Instagram to show off her new knuckle tattoo of the numbers "929." While it might be one of the singer's tiniest tattoos, it's packed with big meaning. The singer co-signed the photo with the caption, "🎂track16 / TRACK2." Fans immediately recognised the set of numbers as a nod to the singer's birthday — Sept. 29 — as well as a subtle teaser to a new track on her upcoming album, Maniac.