ANSI/BHMA code F12 Apartment/ Dormitory (or Exit Lock) function.
Latch bolt retracted by lever/knob from either side. Deadbolt retracted by key outside or inside thumbturn.
Throwing deadbolt locks outside lever/knob. Operating inside lever/knob retracts deadbolt and latchbolt at
the same time, and unlocks outside lever/knob. lnside lever is always free for immediate exit. Auxiliary latch
deadlocks latch-bolt when door is closed.