This is correct. "All rights reserved" was a way of claiming copyright, similar to the © symbol. Open source non-public domain code still has a copyright, it is

This is correct. "All rights reserved" was a way of claiming copyright, similar to the © symbol. Open source non-public domain code still has a copyright, it is just licensed for use under an open source license. https://en.wikipedia.org/wiki/All_rights_reserved https://en.wikipedia.org/wiki/All_rights_reserved