The restriction practice is the practice of requiring an election between two or more distinct inventions in a patent application. There is only allowed to be one unique invention per patent application. In the case where an examiner requires a restriction in a patent application the applicant must make an Election of Species. This election of species means the inventor need to choose between two or more distinct inventions in a patent application to remain in the application. The species which is not elected to stay in the application can be submitted in a divisional application. To require this restriction the examiner must show that the generic claim embraces patentably distinct species or that those species exceed a reasonable number.