3.1 The ceiling and bulkheads including any steps
forming the outer boundary of a cabin (see figures 3.1-1 through 3.1-3)
should have a minimum fire rating of "B-0" where the corridor bulkheads
extend from deck to deck.
3.2 When the corridor bulkheads only extend from
the deck up to the continuous ceilings on both sides of the corridor
(i.e. the corridor bulkheads do not extend to the deck above), the
ceiling of the corridor and of the cabin should have a minimum fire
rating of "B-15" (see figures 3.2-1 through 3.2-5).