Often plugins need to store bits of information against a player and needs to persist that info when the player logs in or logs off.

Provide a way to get a player's profile and set arbitrary data for a given plugin against that data. This should take into account that two plugins may want to set the same keys, so make sure that each plugin is isolated for their profiles

Automatically save and load profiles when player logs out or in, and when the server is shutdown (for saving)