Optical Character Recognition. Technology for machine reading of human readable text.
Open Database Connectivity.
On Demand   Opacity
A printing mode where one label at a time is printed. The label is presented to the operator, separated from the backing paper. When the label is taken from the printer, the next label is printed and presented. Also known as Demand mode.
A bar code verification term. 1).The optical property of a substrate material that measures the show through from the back side or the next sheet. 2).The ratio of the reflectance with a black backing to the reflectance with a white backing. 3).Ink opacity is the property of an ink that prevents the substrate from showing through.
Optical Throw   Optional User Memory
The minimum distance a bar code can be away from a scanner and still be read.
Added memory available on a tag that can be used by any member along the supply chain. Can be used for routing information or other applications to increase tracking efficiency.
Orientation   Overhead
Two possible bar code field orientations are horizontal with vertical bars and spaces (picket fence) and vertical with horizontal bars and spaces (ladder).
The bars and spaces representing the start, stop, function codes and check characters required by some symbologies. These increase the length of the bar code but do not affect the message content.