The cartaz was a pass or permit issued by the Portuguese to ships sailing in the Arabian Sea and the Indian Ocean in the 16th century.
After gaining naval supremacy, the Portuguese made it compulsory for Indian and Asian merchant ships to buy a cartaz; a ship without it was seized and its cargo confiscated.
Even Mughal ships going to Mecca had to take a cartaz. It gave the Portuguese control over sea trade and income.
Chhatrapati Shivaji Maharaj built his own navy and opposed this Portuguese control of the sea.