
      If two or more independent and distinct inventions are claimed in
    one application, the Director may require the application to be
    restricted to one of the inventions. If the other invention is made
    the subject of a divisional application which complies with the
    requirements of section 120 of this title it shall be entitled to
    the benefit of the filing date of the original application. A
    patent issuing on an application with respect to which a
    requirement for restriction under this section has been made, or on
    an application filed as a result of such a requirement, shall not
    be used as a reference either in the Patent and Trademark Office or
    in the courts against a divisional application or against the
    original application or any patent issued on either of them, if the
    divisional application is filed before the issuance of the patent
    on the other application. If a divisional application is directed
    solely to subject matter described and claimed in the original
    application as filed, the Director may dispense with signing and
    execution by the inventor. The validity of a patent shall not be
    questioned for failure of the Director to require the application
    to be restricted to one invention.

Last modified: April 19, 2006