The goals of the Berne Conventionprovided the basis for mutual recognition of copyright between sovereign nations and promoted the development of international norms in copyright protection. European nations established a mutually satisfactory uniform copyright law to replace the need for separate registration in every country. The treaty has been revised five times since 1886. Of particular note are the revisions in 1908 and 1928. In 1908, the Berlin Act set the duration of copyright at life of the author plus 50 years, expanded the scope of the act to include newer technologies, and prohibited formalities as a prerequisite of copyright protection. In 1928, the Rome Act first recognized the moral rights of authors and artists, giving them the right to object to modifications or to the destruction of a work in a way that might prejudice or decrease the artists' reputations. The United States became a Berne signatory in 1988.