I think a good reference for this issue can be found in the wikipedia entry Agreement on Trade-Related Aspects of Intellectual Property Rights
where the following is stated:
The requirements of TRIPS
TRIPS requires member states to provide strong protection for intellectual property rights. For example, under TRIPS:
* Copyright terms must extend to 50 years after the death of the author, although films and photographs are only required to have fixed 50 and to be at least 25 year terms, respectively.(Art. 7(2),(4))
* Copyright must be granted automatically, and not based upon any "formality", such as registrations or systems of renewal.
* Computer programs must be regarded as "literary works" under copyright law and receive the same terms of protection.
* National exceptions to copyright (such as "fair use" in the United States) are constrained by the Berne three-step test
* Patents must be granted in all "fields of technology," although exceptions for certain public interests are allowed (Art. 27.2 and 27.3 ) and must be enforceable for at least 20 years (Art 33).
* Exceptions to the exclusive rights must be limited, provided that a normal exploitation of the work (Art. 13) and normal exploitation of the patent (Art 30) is not in conflict.
* No unreasonable prejudice to the legitimate interests of the right holders of computer programs and patents is allowed.
* Legitimate interests of third parties have to be taken into account by patent rights (Art 30).
* In each state, intellectual property laws may not offer any benefits to local citizens which are not available to citizens of other TRIPs signatories by the principles of national treatment (with certain limited exceptions, Art. 3 and 5 ). TRIPS also has a most favored nation clause.
Many of the TRIPS provisions on copyright were imported from the Berne Convention for the Protection of Literary and Artistic Works
and many of its trademark and patent provisions were imported from the Paris Convention for the Protection of Industrial Property.