The International Patent Documentation Centre (
INPADOC), the
European Patent Office (EPO) and
WIPO recognize the following definitions of simple and extended patent families:
Simple patent family: All patent documents have exactly the same priority date or combination of priority dates.
Extended patent family: All patent documents are linked (directly or indirectly) via a priority document belonging to one patent family. The extended families allow for additional connectors to link other than strictly priority date. These include: domestic application numbers, countries that have not ratified the
Paris Convention, or if the application was filed too late to claim priority. Those are not the only possible definitions of a patent family, however. Another definition, which is broader than the "simple patent family" definition but narrower than the "extended patent family" definition, is to consider that "[a]ll the documents having at least one common priority belong to the same patent family." == See also ==