A more thorough explanation:

A registry is a list or record of something. In law, it can refer to:

1. A probate judge, which is a type of judge who deals with wills and estates.
2. Maritime law, where it refers to the list of ships that are subject to a particular country's maritime regulations. Each ship is listed under the nationality of the flag it flies. For example, if a ship flies the American flag, it will be listed in the American registry.

Another term related to maritime law is enrollment, which is the recording and certification of vessels used in coastal or inland navigation. Enrollment is different from registry because it is used for vessels engaged in coasting trade or home traffic, while registry is used for vessels engaged in foreign trade.

For example, if a ship is used to transport goods between two ports in the same country, it would be enrolled in the country's registry. But if the ship is used to transport goods between two different countries, it would need to be registered in the country where it is based.