patch code

A parallel pattern of alternating black bars separated by spaces and placed near the leading edge of a paper document. Sometimes used to separate documents and batches or to perform identification.
Patch codes are a set of 6 distinct barcode patterns (1, 2, 3, 4, 6 and T) that are typically used as document separators when scanning.
A patch code is a pattern of parallel, alternating black bars and spaces (i.e. a barcode) that is printed on a document. When scanning the document the patch code can be recognised and acted upon. The patch code may be recognised by the scanner itself (usually in the top-end expensive scanners) or by the scanning or processing software. Exactly what action is taken depends upon the design of any given system.
The most typical use of a patch code is distinguish where one document ends and another begins when a pile of documents are loaded into the sheet-feeder (ADF) of a document scanner.