OMR OMR (Optical Mark Reader) codes are a set of strokes that can be used by an enveloping machine to, for example, identify the first and last pages in a document. Depending on the requirements of the enveloping machine, you can define: • Standard OMR codes (STD) • Generic OMR codes • Bar codes (where the strokes in an OMR code definition can have different thicknesses) In this section • Defining OMR codes • STD strokes • Bar functions • OMR examples