KU is slang for CIA, there are two KU’s in K4 :
O B K R U O X O G
H U L B S O L I F
B B W F L R V Q Q
P R N G K S S O T
W T Q S J Q S S E
C Z Z W A T J K L
I D I A W I N F B
A N Y P V T T M Z
F P K W G D K Z X
T J C D I G C I A
H U A U E K C A R