Abstract: A multifunction hub core for a mortise lock comprises a mortise lock body having a deadbolt operable by a first control member on the outside of a door and a second control member on the inside of the door, and a deadbolt arm with slots for receiving a hub core. The deadbolt arm is rotatable inside the mortise lock body to move the deadbolt between retracted and projected positions. The hub core disposed in the deadbolt arm comprises projections allowing it to fit in the deadbolt arm slots in one of two positions. The first position allows the second control member to move the deadbolt between retracted and projected positions and is known as the standard function. The second position allows the second control member to retract the deadbolt from a projected position, but cannot project the deadbolt from a retracted position, and is known as the classroom function.