This term is used by "sign hunters" which means to hunt for signs that you want or like, signs that are hard to get. That you can retrieve for "points".
Background- Created by three hooligans looking for a good time aka Omega,Asaytu,Rey the rulers of Lower Town Salut
Omega: "Wanna go sign hunting"
Rey: "For sure"
Asaytu: "It's in our blood"