Motorola SYMBOL LS9203 Reference Manual page 329

Symbology The structural rules and conventions for representing data within a particular bar code
type (e.g. UPC/EAN, Code 39).
Tolerance Allowable deviation from the nominal bar or space width.
UPC Universal Product Code. A relatively complex numeric symbology. Each character
consists of two bars and two spaces, each of which is any of four widths. The
standard symbology for retail food packages in the United States.
Visible Laser Diode A solid state device which produces visible laser light.
(VLD)
Glossary GL-5