IP and Copyright are two different concepts. Protected IP tends to break into trade secrets (protected by secrecy) and patents (protected by disclosure).
Similarly, trade dress and trademarks are related but different, and in USA most Trademarks™ are not Registered® (although to get ® you generally use ™ along the way), and most trade dress is not either.
Similarly, trade dress and trademarks are related but different, and in USA most Trademarks™ are not Registered® (although to get ® you generally use ™ along the way), and most trade dress is not either.
See also:
- clean room design: https://en.wikipedia.org/wiki/Clean-room_design
- trade dress: https://en.wikipedia.org/wiki/Trade_dress
Amusingly, the packaging of a dress is trade dress, but the dress design itself isn't protected.