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Data Matrix is a 2D bar code symbology gaining widespread use on things as diverse as bills, invoices, statements, and the postmarks on US mail. Data Matrix is quickly becoming the 2D bar code of choice, especially in situations where space is at a premium.
Data Matrix is a compact 2D symbology capable of holding relatively large amounts of data when compared to older 1D symbologies like Code 128 or Code 39. Data Matrix symbols can also be made smaller than the same data encoded in a PDF 417 bar code.
Data Matrix is the basis for UID barcodes (unique identification barcodes) that are specified the Dept. of Defense.