At its June 2004 meeting, the Standing Committee on Rules of Practice and Procedure asked the Appellate Rules Advisory Committee to ask the Federal Judicial Center to conduct empirical research that would help the Standing Committee in its consideration of a proposed new Federal Rule of Appellate Procedure 32.1, which would permit attorneys and courts in federal appeals in all circuits to cite the court's unpublished opinions. The Center's research effort consisted of three components: (1) a survey of judges, (2) a survey of attorneys, and (3) a survey of case files. The rule, as amended and approved by the Judicial Conference in September 2005 and approved by the Supreme Court in April 2006, applies only to opinions issued in 2007 or later. The rule became effective December 1, 2006.