Independent can refer to the status of a pirate who is not part of a crew or a crew which does not belong to a flag. A pirate or crew must be independent to make a crew or flag, respectively.
All pirates and crews start off as independent, but if a pirate who is officer or higher in a crew has referred a friend, then that friend, if he/she plays on the same ocean, will automatically join that crew as a cabin person.
On the Obsidian Ocean, independent pirates are "neutral" and do not belong to either of the two factions.
Reasons to be independent
Some pirates may choose to be independent if they are not frequent players, or mainly play parlor games or crafting puzzles. Additionally, many wealthy players store ship or building deeds on an independent alt pirate to safeguard them from war, or to minimise the risk of theft from ships. This is considered cheaper and more convenient than creating a one-pirate crew. However, there have been cases where deed pirates have turned dormant accidentally and have been subsequently purged.
Crews may choose to be independent. This is sometimes done to avoid the effects of war.