A flag of convenience is a flag of one country, flown by a ship owned by another country. Doing this can avoid taxes and make registration easier for the ship owner, and makes money for the country providing the flag.
Other countries with stricter requirements for ship registration do not like this as it deprives them of money, and is possibly more dangerous and unfair to ship workers.
The International Transport Workers' Federation (ITF) maintains a list of countries that use their flag for this purpose.
Countries declared FOCs by the ITF
As of 2003, these 28 countries have been declared flag-of-convenience countries. There are other countries apart from these that will also sell the use of their flag.