In some countries, specific rules may apply that alter or add to the general rule of life plus 70 years (for example, granting extensions for the period of World War II). In addition, some countries had different copyright terms that were in effect before adoption of the general rule. For example, the United States did not adopt a “life plus” copyright duration until 1978. These differences in national laws imply the fact that in some cases a specific work can still be in copyright in some countries but out of copyright (that is, in the public domain) in others.
