46 CFR § 78.47-10
Manual alarm boxes
April 15, 2021
(a) In all new installations, manual alarm boxes shall be clearly and permanently marked “IN CASE OF FIRE BREAK GLASS.” Existing boxes not so marked with the same or equivalent wording, shall be identified either on the box or adjacent bulkhead in at least 1⁄2 inch letters “IN CASE OF FIRE BREAK GLASS.” All manual alarm boxes shall be numbered in red on the adjacent bulkhead with at least 1⁄2 inch figures. The number shall agree with the number of the zone.
(b) [Reserved]