A legal order that allows a person or entity to take legal action against an unknown party or parties…

A John Doe (or Ashok Kumar) order is an injunction granted against unnamed or unknown defendants, used in Indian IP cases against anonymous infringers and pirates; the Delhi High Court first granted one in Taj Television v. Rajan Mandal (2003).

An Anton Piller order permits a search of premises and seizure of evidence, and a Mareva injunction freezes a defendant's assets so they are not moved out of reach. Plea bargaining is a criminal-procedure device for a reduced sentence and has nothing to do with unknown parties.