MiniCode
From Just Solve the File Format Problem
If there's a MaxiCode, then there needs to be a MiniCode too, right? Created by a company called Omniplanar (apparently part of Honeywell), the MiniCode format of 2-D bar codes stores two sets of data at different levels of magnification, a short item referred to as the "license plate", and a longer one called the "data file".
License Plate
The "license plate" data consists of 200 bits stored in a 15 x 15 array of square cells, which can be white or black. A 5 x 5 group in the center is used as a finder pattern and is not part of this data.
Data file
The data file is encoded using smaller squares called "subcells" which are contained within the cells of the license plate data.