Section 108.631 - Fixed fire extinguishing system controls(a) Each cabinet or space that contains a valve, control, or manifold of a fixed fire extinguishing system must be marked in conspicuous red letters at least 2 inches high: "[CARBON DIOXIDE/CLEAN AGENT/FOAM/WATER SPRAY-as appropriate] FIRE APPARATUS.".(b) Instructions for the operation of a fixed fire extinguishing system must be posted next to a fire apparatus described in paragraph (a) of this section.CGD 73-251, 43 FR 56808, Dec. 4, 1978, as amended by USCG-2006-24797, 77 FR 33882 , June 7, 2012