Each one of the 89 United States District Courts, as well as each of the 13 United States Courts of Appeal, have their own "local" rules that attorneys and pro se litigants are expected to follow. Since these rules can differ from court to court, it is important to check these local rules before appearing before the court.
Local rules can be found on the official websites for each of the federal courts.
Includes federal rules of practice and procedure which govern litigation in the federal courts, as well as rules that govern appearing and litigating in specific courts.