The 1886 Berne Convention first established recognition of copyrights among sovereign nations, rather than merely bilaterally. Under the Berne Convention, copyrights for creative works do not have to be asserted or declared, as they are automatically in force at creation: an author need not "register" or "apply for" a copyright in countries adhering to the Berne Convention. As soon as a work is "fixed", that is, written or recorded on some physical medium, its author is automatically entitled to all copyrights in the work, and to any derivative works unless and until the author explicitly disclaims them, or until the copyright expires. The Berne Convention also resulted in foreign authors being treated equivalently to domestic authors, in any country signed onto the Convention. The UK signed the Berne Convention in 1887 but did not implement large parts of it until 100 years later with the passage of the Copyright, Designs and Patents Act 1988. Specially, for educational and scientific research purposes, the Berne Convention provides the developing countries issue compulsory licenses for the translation or reproduction of copyrighted works within the limits prescribed by the Convention. This was a special provision that had been added at the time of 1971 revision of the Convention, because of the strong demands of the developing countries. The United States did not sign the Berne Convention until 1989.