(a) The manual operating positions for automatic fire dampers in ventilation ducts passing through main vertical zone bulkheads shall be identified by red day light-reflecting letters at least \1/2\ inch high ``VENTILATION FIRE DAMPER.'' In addition, the open and closed positions shall be similarly marked.
(b) [Reserved] [CGFR 65-50, 30 FR 16955, Dec. 30, 1965, as amended by CGD 67-87, 32 FR 19181, Dec. 20, 1967]