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Appendix D
Glossary
This glossary focuses on terms related to QR Codes and Data Matrix codes which are
matrix-type 2-dimensional codes. There may be some parts of this glossary that do not
apply to other types of 2-dimensional codes.
Data Matrix
Data Matrix codes were developed by I.D. Matrix, and are used extensively in the semi-
conductor and electronics industries. Data Matrix codes have a relatively large data
capacity for their size. There are several different types of Data Matrix, differentiated by
their error correction method. The ECC200 is the most commonly used type.
QR Code
The “Quick Response Code” type is a 2-dimensional code that was developed in Japan.
High-speed reading is possible with QR Codes, but the code size is quite large com-
pared to other 2-dimensional codes.
Error Correction
This term is used to describe the function which detects and corrects errors using a spe-
cial mathematical technique (commonly known as the “Reed-Solomon” method). Using
this function, reading is possible, to a certain extent, for codes with poor printing quality
or that are damaged. There are, however, limits on the extent to which correction is pos-
sible, and reading may not be possible for codes if the damage is extensive. There are 2-
dimensional codes for which the error correction level can be selected. (For example,
with QR Codes, error correction levels of 7%, 15%, 25%, or 30% are available.)
