Some basic rules governing appeals are found in Articles 55 and 57 of the New York Civil Practice Law and Rules, but they are not detailed enough to fully provide for a comprehensive system of appellate procedure. Prior to September 2018, and unlike other states that have statewide rules of appellate procedure, there was no set of appellate procedure rules shared by all four departments beyond the rudimentary set in the CPLR. Instead, each Department of the Appellate Division filled in the CPLR's gaps by promulgating its own individual set of rules governing more specific details of practice before that court. The result was considerable diversity in appellate procedure between the departments, which extended to matters as basic as the form and formatting of appellate briefs, the deadline to perfect an appeal after filing of the notice of appeal, appellate motions, and oral argument.