Consider the following hypothetical situation. Japan is a member of the Paris Convention as is Norway. A Japanese national, hereinafter called the "Japanese filer", makes an invention in Japan, keeps their invention secret and then files a patent application at the Japanese Patent Office on January 10, 1995. This application can be either for a Japanese patent or for a Japanese utility model, as the particular choice will not affect this hypothetical. Some time thereafter the Japanese filer advertises and sells products incorporating the invention. Purchasers of the products can readily deduce the invention after they have purchased the product. The Japanese filer is not precluded from filing corresponding patent applications in member countries of the Paris Convention, such as Norway, so long as (i) the foreign applications are filed by January 10, 1996 (assuming the invention becomes public before that date), that is, one year from the first patent application filed in a Paris Convention country (which, in this case, is Japan) and (ii) a claim for convention priority is appropriately filed. While this is a tremendous benefit, in terms of member countries, one must be aware, however, that not all countries are members of the Paris Convention.
In the example outlined above, the disclosure of the invention soon after filing at the Japanese Patent Office would preclude the Japanese filer party from being able to obtain a valid a non Paris Convention member country whose novelty rules require that no public disclosure of the invention occur before a patent application is filed there. One such country is Brunei while another is Taiwan[*]. Since neither Brunei nor Taiwan is a member of the Paris Convention, it follows the general rule noted in "Patents are of National Origin" regarding the required novelty of the invention. That is, Taiwan's novelty requirements must be abided by. Taiwan will not allow one to obtain a patent for an invention if the invention has been made public prior to filing for a patent in Taiwan. To file a valid patent application in Taiwan, the Japanese filer would have to file a patent application in Taiwan before making his or her invention public, which occurs, for example, by selling their products.
Now assume that another party, a "Norwegian filer" makes the very same invention as did the Japanese filer. The Norwegian filer files their patent application for that invention in Norway on June 1, 1995. As long as the Japanese filer has filed his or her application in Norway by January 10, 1996, the Norwegian Patent Office will consider the first filer for to be the Japanese filer. It will award the Japanese filer with a January 10, 1995 date as their "effective filling date". This date precedes the Norwegian filer's June 1, 1995 actual filing date, and therefore, the patent in Norway will be granted to the Japanese filer (assuming the invention is otherwise patentable). Had the Japanese filer missed the one year grace period by filing, for example, on January 20, 1996 in Norway, the Norwegian patent would be awarded to the Norwegian filer as Norway would no longer give the Japanese filer the earlier effective filing date. However, if the Japanese filer had started selling their products before the Norwegian filer actually filed their patent application, those activities of the Japanese filer might well invalidate any patent issuing to the Norwegian filer.