Most orders of any court are not accompanied by opinions, but are simply stated in memorandum form. The Supreme Court issues thousands of such memorandum orders each year, granting or denying such requests as applications for review, applications for permission to appear in forma pauperis, applications for permission to file briefs amici curiae, or petitions for rehearing.
Some memorandum orders effectively decide cases; the denial of a petition for certiorari is one example, and another is the dismissal of an appeal "for want of a substantial federal question." Occasionally the Court summarily affirms the decision of a lower court, issuing no opinion but only a memorandum order. The denial of certiorari generally has little force as a precedent; however, both lower courts and commentators do draw conclusions concerning the Court's view when they see a consistent pattern of refusal to review lower court decisions reaching the same conclusion. The summary affirmance of a decision in a memorandum order does establish a precedent, but the precedent is limited to the points necessarily decided by the lower court, and does not extend to the reasoning in that court's opinion. The practice of deciding major issues through memorandum orders is often criticized on the ground that decisions will not be understood as principled if they are not explained.
Kenneth L. Karst
Brown, Ernest J. 1958 The Supreme Court, 1957 Term—Foreword: Process of Law. Harvard Law Review 72:77–95.