[1] The licensing of vessels by the Portuguese was initiated by Prince Henry the Navigator in 1443,[2] with the consent of the king and the Pope, when he decreed a monopoly on navigation in the west African coast, starting a Portuguese Mare clausum policy in the Atlantic Ocean.
Ships began to be licensed by Portugal, which authorized and supported navigation, in exchange for part of the profits (usually 20%, "the fifth"), encouraging investment in exploration travels by Portuguese and foreigners.
[3] The "cartazes" licensing system was created in 1502 to control and enforce the Portuguese trade monopoly over a wide area in the Indian Ocean, taking advantage of local commerce: the cartaz was issued by the Portuguese at a low cost, granting merchant ships protection against pirates and rival states, which then abounded in these seas.
Officially, no vessel was permitted to sail in the Indian coast without this document, risking losing their cargo, being attacked and even sunk by the Portuguese - mainly Muslim, Hindu and Malay merchant ships.
The cartaz system eventually introduced a new word, kadalaas (കടലാസ്) to the Malayalam language of Kerala which is still used to denote any kind of paper.