Rider

Rider, ^* practice, legislation. A schedule or small piece of paper or parchment added to some part of the record; as, when, on the reading of a bill in the legislature, a new clause is added, this is tacked to the bill on a separate piece of paper, and is called a rider.

^* From Bouvier's Law Dictionary, 1856 Edition. Please see Bouvier's Legal Abbreviations & Abbreviated References for help with obscure nomenclature & references.