Ship identifier

A ship identifier refers to one of several types of identifiers used for maritime vessels.

An identifier may be a proper noun (La Niña); a proper noun combined with a standardized prefix based on the type of ship (e.g. RMS Titanic); a serial code; a unique, alphanumeric ID (e.g. A123B456C7); or an alphanumeric ID displayed in international signal flags (e.g. , representing U6CH).

Some identifiers are permanent for a ship while others may be changed at the owners' discretion although regulatory agencies will need to approve the change.

Modern ships usually have several identifiers.

In addition to proper nouns, types of ship identifiers include:

Stern of the Belgian vessel Talisman displaying its ENI number: 06105000
USS Arleigh Burke displays hull number 51