2.6.1.2 Unknown authorship
If a work has been published without any information about the author or if no authorship information can be assigned to a specific person, it is referred to as unknown authorship. In such cases, it is not possible to calculate the general term of protection of 70 years (or 50 years in the case of computer programs) after the death of the author.
According to Art. 31 Para. 1 CopA, copyright protection for published works expires 70 years after they are published. If a work has been published in instalments, such as in the case of a multivolume work whose volumes have been published individually over a specific period, copyright protection expires 70 years after the final instalment.
However, if the identity of the author becomes known before the 70-year term of protection expires, the general terms of protection come into effect. This means that the protection expires 70 years (or 50 years in the case of computer programs) after the death of the author (Art. 31 Para. 2 CopA).