For most lawyers, the mandate is an abstract concept that they seldom consider. But the law of mandates provides a number of principles that can be of use to the appellate practitioner.
In most instances, the mandate involves only ministerial actions. It is issued by the clerk of the appellate court. See U.S. v. Rivera, 844 F.2d 916 (2nd Cir. 1988). The applicable court rules define the content of the mandate and the procedure and timing for its issuance. See Sup. Ct. R. 45; Fed. R. App. P. 41; D.C. Cir. R. 41.