Definition
"Unreleased" means not made available to the public or not distributed. Think of a movie that's been filmed but hasn't hit theaters yet, or a song that's recorded but not yet put on an album. The term implies something is being held back from general consumption. Unlike "private," "unreleased" suggests potential future availability. It's similar to a prototype that's still in development. It differs from "withdrawn", implying something had been released and then taken back.