FAR Sec. 23.853:
Passenger and Crew Compartment Interiors
For each compartment to be used by the crew or passengers: (a) The materials must be at least flame-resistant; (b) [Reserved] (c) If smoking is to be prohibited, there must be a placard sostating, and if smoking is to be allowed- (d) In addition, for commuter category airplanes the followingrequirements apply: (Section d snipped – […]