Yellow Sign token
The Yellow Sign token is used whenever the The King in Yellow herald is used. Whenever the terror level in Arkham increases (for any reason), the investigators must either place the Yellow Sign on the terror track or on the doom track. When placed on the terror track, a random Blight is drawn from the blight deck, and its effects stay in play for the remainder of the game. If it is placed on the doom track, it is functionally identical as a doom token in all respects.