They differ from an intervener in that they are drafted by non-parties, and Rule 29 of the Federal Rules of Appellate Procedure requires that, in order for a court to grant leave for them, they should raise relevant issues not raised by the parties in a case.
Justice Scalia notably attacked reliance on these in Jaffee v. Redmond. They differ from an intervener in that they are drafted by non-parties, and Rule 29 of the Federal Rules of Appellate Procedure requires that, in order for a court to grant leave for them, they should raise relevant issues not raised by the parties in a case. The Bush administration submitted two during the University of Michigan affirmative action decisions and they are often filed by advocacy organizations. For 10 points, name this type of legal brief, from the Latin for "friend of the court." 
Justice Scalia notably attacked reliance on these in Jaffee v. Redmond.
Amicus curiae briefs 