Abstract: A method of decoding a coding pattern disposed on or in a substrate. The method comprises the steps of: (a) operatively positioning an optical reader relative to a surface of the substrate; (b) capturing an image of a portion of the coding pattern; (c) sampling and decoding a registration symbol contained in the imaged portion; (d) determining, using the decoded registration symbol, an encoding format; and (e) using the determined encoding format to sample and decode data symbols in the imaged portion. The coding pattern comprises a plurality of macrodots encoding data symbols and registration symbols, wherein each data symbol is represented by d macrodots, each of the d macrodots occupying a respective position from a plurality of predetermined possible positions p, the respective positions of the d macrodots representing one of a plurality of possible data values. Each registration symbol, or a set of the registration symbols, identifies an integer value of d and thereby the encoding format.