ORIENTATIONAL DISAMBIGUATION FOR SELF-CLOCKING GLYPH CODES

An optically readable record for storing encoded information comprises (1) a recording medium, (2) a self-clocking data code for encoding the information, with this data code being composed of glyphs that are written in a two dimensional code field on the recording medium on centers that are spatially distributed in nominal accordance with a predetermined spatial formatting rule. The glyphs are defined by respective symbols that are selected from a finite set of optically discriminable symbols to encode the information. Further, there is at least one additional glyph pattern that is written on the recording medium in nominal accordance with the aforementioned spatial formatting rule, with this additional code pattern being discriminable from the data code and being selected to disambiguate data codes that are rotated and/or reflected.