Keyboard Wedge Decoder — See Decoder.
Ladder Code — A bar code printed in a vertical position such that the bars can be thought of as rungs on a ladder. Contrast with Picket Fence.
Light Pen — See wand.
LOGMARS (Logistic applications for Marking And Reading Symbols) — A Department of Defense program intended manage inventory by placing Code 39 bar code symbols on all items sold to the Federal Government.
Manufacturer Identification Number — The Manufacturer Identification Number is a six digit number assigned to a manufacturer by the UCC (Uniform Code Council). This number is found on the left side of the U.P.C. number. The number is composed of a number system character and a five digit manufacturer’s code.
Matrix Symbols — A symbol which appears as a checker board; they are most likely square in shape, and contain some form of unique “finder pattern,” which distinguishes them from others and provides a decoding reference for scanners.
Mil — One thousandth of an inch (0.001 inch), or approximately 0.0254 millimeter. Commonly used to refer to the width of bar code elements, for example, 0.013 inch would be expressed as 13 mils.
Minimum Reflectivity Difference — A white space will reflect more light than a black bar. The minimum reflectivity difference is the variance between the least amount of light reflected by the narrowest white space, and the most amount of light reflected by the widest black bar. Minimum reflectivity difference is one measure of the read-ability of the bar code symbol.
Mis-Read — The situation which occurs when a bar code reading device detects a bar code symbol incorrectly (different than intended). A mis-read may be due to a defective symbol, to a mis-match between the reading device and the printed symbol, or to a defective reader or decoder. A mis-read may occur as as substitution error (the reader substitutes an incorrect character) or as a transposition error, or as a missing character in a character string.
Module — The narrowest of bars, sometimes referred to as the X dimension. Wider bars and spaces are stated as multiples of this narrow bar.
Modulo Check Character(s) — The modulo check character is based on the remainder in a mathematical formula where characters within the data string are assigned weighted values, summed and then divided by the modulus. This value is then appended to the data string. Modulo check characters are used to ensure the accuracy of a data scan.
Number System Character — The first digit or left hand digit in a U.P.C., number. This digit identifies the type of manufacturer or how the bar code will be used. For example “0, 6 and 7” are generally used in the retail industry, while “3” is assigned to the health and drug manufacturing industries.