Each control cabinet or space containing valves or manifolds for the various fire extinguishing systems must be distinctly marked in conspicuous red letters at least 2 inches high: ``CARBON DIOXIDE FIRE EXTINGUISHING SYSTEM,'' ``HALON EXTINGUISHING SYSTEM,'' or ``CLEAN AGENT EXTINGUISHING SYSTEM,'' as appropriate. [USCG-2006-24797, 77 FR 33890, June 7, 2012]