noun: (law) A number affixed to a document indicating its number in a series of documents, usually with respect to evidentiary documents being provided to the other party in a legal proceeding. Initially should be referenced as (Bates stamp p.1); subsequent references within the same document should follow as (p.2), (p.3), etc or (Bates stamp p.4).
verb: To stamp or label documents with Bates numbers.
