To supersede the requirements of Subsections 3.1.8., 3.1.9. and 3.2.8., and require scissors stairs and other contiguous exit stairways to be separated from each other by smoke-tight fire separations.
This is to limit the probability that fire will spread from one exit to another exit, which could lead to delays or ineffectiveness in fire emergency response operations, which could lead to the further spread of fire, which could lead to damage to the building.