Section 405 establishes detailed requirements for stages, platforms, and associated areas in assembly occupancies and other buildings. Stages include spaces used for theatrical productions, lectures, presentations, and performances. The proscenium wall separating the stage from the audience area must be constructed of noncombustible materials with a 2-hour fire-resistance rating to prevent fire spread from stage to audience areas. Proscenium openings must be protected with a safety curtain of approved fire-rated fabric capable of closing to seal the opening within 60 seconds. Stage curtains (teasers and legs) used for scenery must be flame-spread rated to Class B or better. Fly galleries, catwalks, and lighting positions above the stage must have flooring with limited openings and railings preventing falls. Basement areas below stages housing stage equipment must be noncombustible or separated from the stage area. Sprinkler systems are required throughout stage areas with specific density calculations appropriate for ceiling heights and flame spread hazards. Lighting equipment must be installed to prevent ignition of scenery, with clearance distances specified from combustible materials. Dressing rooms and actor preparation areas associated with stages must meet standard exit requirements with separate egress not returning to the stage. Green rooms and other backstage spaces require appropriate exits and fire protection. Prop storage areas must be separated from active stage areas and protected with sprinkler systems. Sound and lighting control rooms must be noncombustible and equipped with emergency communication systems.