Used by the routines at 25581, 25656, 25677, 26639, 26752, 27144, 32379 and 61463. Blanks out the address of the routine held in bytes 9 and 10 of the character's buffer, which has the effect of making the routine at 25296 consider the address held in bytes 3 and 4 of the character's buffer (normally a routine address from the command list) as the next candidate for controlling routine.