20. (1) Every ship in respect of which an application for registration is made, shall, before registration, be marked in the prescribed manner permanently and conspicuously and to the satisfaction of the Registrar. (2) The marks required by this section shall be permanently continued and shall not be altered except in the event of any of the particulars thereby denoted being altered in the manner provided by this Ordinance, except to evade capture by the enemy or by a foreign ship of war in the exercise of some belligerent right. (3) If an owner or master of a Bangladesh ship neglects to cause his ship to be marked as required by this section, or to keep her so marked, or if any person conceals, removes, alters, defaces, or obliterates, or suffers any person under his control to conceal, remove, alter, deface, or obliterate any of the said marks, except in the event mentioned in sub section (2), he shall, for each offence, be punishable with fine which may extend to twenty thousand Taka; and on a certificate from a Surveyor that a ship is insufficiently or inaccurately marked, the ship may be detained until the insufficiency or inaccuracy has been remedied.