TRUNCATION 

The success of the Universal Product Code System depends upon being able to easily identify individual products at a retailer front-end by rapidly moving these products past a symbol reading scanner. To insure maximum productivity, the system was designed to require a minimum effort in presenting and reading the UPC symbol with the scanner. Omnidirectional symbol scanning is basic to the system's success.

The UPC symbol geometry as described in the Symbol Specification manual facilitates omnidirectional scanning. Any truncation or shortening of the bar height from that specified in the manual leads to a degradation of this scanning ability. Truncation might consist of decreasing the specified bar height by a fraction of an inch or, in other cases, by decreasing bar height to the point where the overall height of the symbol becomes only a fraction of an inch. The more a symbol is truncated or shortened the more precisely it must be presented to the scanner for reading and the poorer the productivity becomes.

No truncation is permitted by the UPC Symbol Specification. It is recognized, however, that in some cases the package size and/or shape make it impossible to contain a "full height" UPC symbol. Since symbol height is directly related to productivity at the retail front-end, the process of truncation should be used only to the degree necessary and only as a last resort where no symbol at all would be the only other alternative. Truncation should never be used on packages large enough to accommodate a full size symbol.

It might also be interesting to note that a truncated symbol is somewhat more tolerable on small packages than on larger ones primarily because of the small package size. A truncated symbol requires precise orientation to a scanner. The shape of a small package, for instance individual packs of chewing gum, will assist a checker in properly orienting the packages to a scanner window. A larger package would lead the checker to expect a full height, or omnidirectional reading symbol and, in addition, would provide little visual guidance for orienting the product to read a truncated symbol.