There is a difference between smoke detectors and smoke alarms.
Smoke detectors are part of a fire alarm system.
Smoke alarms are stand alone units that are required to be interconnected to alarm when any one of the units is activated. (for new construction)
Smoke alarms are required in residential occupancies.
Fire alarm systems are required in commercial applications.
Make sure you are using the correct part of your building code document for the occupancy being protected.
In other words, don't apply the rules for a fire alarm system's smoke detectors to residential smoke alarm situations.
