the entire body of rats during the ratline is called a "rat mass." since rats are not officially fourth classmen until after breakout, the rat mass is also not officially considered a graduating class until that time either. prior to breakout, the rat mass is given a different style of year identifier to emphasize this difference. the year identifier starts with the year of the current graduating class (their dykes' class), followed by a "+3" to indicate the anticipated year of their own class. for example, cadets that make up the class of 2022 were considered the "rat mass of 2019+3" as the members of their dykes' class graduated in 2019 and they themselves will graduate three years onward from then.