OSGeo has now received legal advice on copyright headers in source code files. This advice is summarised here for the benefit of all projects:
- Copyright headers in source code files are not required to enforce copyright.
- Works still under copyright when the Berne Convention was adopted (1992 in the United States) are protected under this convention.
- Works created after the Berne Convention was adopted are also protected.
- There is no need to include a copyright header for a source code file created or modified after the Berne Convention was adopted. A modified source code file is a new work.
- Source code files created before the adoption of the Berne Convention and not modified since its adoption should include a copyright header with the dates of creation and modification. These dates support the assertion that these files are covered by the Berne Convention.
- Both individual source code files and the project source as a whole are copyrighted works.
An informative header that names the project, links to to project page, and references the licence is informative, and while not legally binding, might deter some infringers (at least they were warned file-by-file that the code is open source).
Note that the author of this blog post is not a lawyer and this post has not been reviewed by a lawyer. This post should not be construed as legal advice.