Open topic with navigation

MSI Plessey is a numeric, variable length symbology originally developed by the Plessey Company of England in the early 1970s. However, the most widely supported version, "MSI" Plessey, is currently maintained by Symbol Technologies, Inc.

Like Interleaved 2-of-5 and UPC, Plessey is an all-numeric language. It has an interesting simplicity in that the barcode pattern for each character is a simple binary pattern of "zeros" and "ones" that directly represent the given number. Accordingly, with casual familiarity with the code, you can actually read the barcode with your eyes. However, Plessey does not encode numbers efficiently, and other characteristics of the language make it one of the most error-prone of all barcode languages. Accordingly, the MSI company came out with a revised standard for the Plessey language (now called MSI Plessey) which employed a second check digit. This improved the reliability of the language enough so that the MSI version of the code has continued in use in specialty applications.

Although Plessey was originally developed for use in the library industry, its use in libraries is now quite rare. Today, MSI Plessey is the most common barcode language used for inventory tracking on the shelves in supermarkets. While MSI Plessey is not actually used on the products themselves (which contain UPC codes), it is used on the front edge of the shelves to indicate where each product is stored.

For additional information regarding the MSI Plessey symbol specifications, please contact Symbol Technologies. (As Symbol purchased MSI in the early 1990s, they now control the MSI Plessey barcode language.)