permissive intervention

noun | \ ˌin-tər-ˈven-chən \ | in·ter·ven·tion

1. : the act or an instance of intervening; specifically : the act or procedure by which a third party becomes a party to a pending proceeding between other parties in order to protect his or her own interest in the subject matter of the suit — compare impleader, interpleader, joinder : the act or procedure by which a third party becomes a party to a pending proceeding between other parties in order to protect his or her own interest in the subject matter of the suit — compare impleader, interpleader, joinder

   Note: Intervention developed as a procedure in equity courts. There is some overlap between joinder and intervention because of the merger of law and equity in federal practice.

   — intervention of right
   : intervention allowed in federal civil procedure when a statute grants an absolute right to intervene or when the applicant claims an interest in the subject of the proceeding that the applicant may be impeded from protecting by the disposition of the proceeding Note: Intervention of right will not be granted if the court considers that the applicant's interest is already adequately represented.

   — permissive intervention
   : intervention allowed in federal civil procedure when a statute grants a conditional right to intervene or when the applicant's claim has a question of law or fact in common with the proceeding