Broadly, ships flying flags of Party States, when on international voyages. Each chapter (I to XII) defines the ships to which that chapter applies. Application may depend on type of ship (e.g. chapter X – High Speed Craft), or date of build (e.g. chapter II-1 – Construction – subdivision and stability, machinery and electrical installations), area of operation (e.g. chapter V – Safety of navigation), tonnage (e.g. chapter IV – Radio communications) or cargoes (e.g. chapter VI – Carriage of cargoes and oil fuels). Each chapter may also exempt certain ships from the chapter’s requirements.