ANSI/BHMA code F15 Hotel function.
Latch bolt retracted by key from outside or by lever/knob inside, Outside lever/knob is always fixed.
Dead bolt projected by turn from inside and all keys except emergency and display key are shut out.
Operating inside lever retract both bolts.
Auxiliary latch deadlocks latchbolt when door is locked. lnside lever is always free for immediate exit.