From the wikipedia clean room page: > Typically, a clean-room design is done by having someone examine the system to be reimplemented and having this person wr

From the wikipedia clean room page: > Typically, a clean-room design is done by having someone examine the system to be reimplemented and having this person write a specification. This specification is then reviewed by a lawyer to ensure that no copyrighted material is included. The specification is then implemented by a team with no connection to the original examiners. Without the disconnection between examiners and implementers, it's only slightly similar to a clean room. And we have new case law to consider: an API may be subject to copyright, and those unit tests are highly suspect under that lens.