1. A method for separating and categorizing documents comprising: manually stamping a page of each of a plurality of documents of a batch of documents with a document separator stamp comprising first and second machine recognizable patterns applied on a same page of the respective document, the first and second machine recognizable patterns being spaced by a designated field for receiving a handwritten user-applied category code, the first and second machine recognizable patterns defining left and right boundaries for the designated field; manually applying a category code to each document separator stamp, including handwriting the category code in the designated field; scanning the batch of the documents to form a scanned batch of documents, each document having a page having a document separator derived from the document separator stamp; processing the scanned batch of documents to identify pages that contain the document separator, the processing including identifying at least one of the first and second spaced patterns, with an algorithm which is capable of detecting both of the spaced patterns; for each of a plurality of document pages for which a document separator is identified: locating the corresponding designated field using a detected location of at least one of the spaced patterns; 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; and wherein the processing, locating, identifying, separating and assigning are performed with a computer processor.