1. A method for separating and categorizing documents comprising: receiving a scanned batch of documents comprising a plurality of scanned documents to which document separator stamps have been applied before scanning, each document separator stamp comprising first and second machine recognizable patterns applied on a same page of a document, the first and second patterns being spaced by a designated field for receiving a user-applied category code; processing the scanned batch of documents to identify pages that contain a document separator derived from a stamp, the processing including identifying at least one of the first and second spaced patterns; for each of a plurality of document pages for which a document separator is identified: locating the corresponding designated field; and identifying the category code associated with the designated field; separating the document containing the identified separator from other documents in the batch based on at least the identified separator; and assigning a document category from a set of document categories to the document, based on the identified category code.