What is the proper interpretation of the phrase "any person... employed or engaged in any capacity on board a ship, on the business of the ship" in the last answer?

According to para. 2.2.1 of MSN 1767, it is taken to mean a person, employed either directly by a shipping company or through a manning agency, whose usual place of work is on board a seagoing ship, and includes masters and crew members, and resident entertainers and franchise employees on passenger ships. Boatmaster's Licence holders on sea-going passenger vessels (carrying more than 12 passengers) are also "seafarers".