The confusing thing about this question is that "other similar methods" includes QR codes [1] -- they're just a generalization of 1-dimensional bar codes to a 2

The confusing thing about this question is that "other similar methods" includes QR codes [1] -- they're just a generalization of 1-dimensional bar codes to a 2-dimensional matrix, with some error correction and alignment information to make scanning them theoretically more reliable. They also have native support for some data types, like URLs. Other than that, it's mostly that they have some traction. [1] https://en.wikipedia.org/wiki/Barcode#Matrix_.282D.29_barcodes https://en.wikipedia.org/wiki/Barcode#Matrix_.282D.29_barcod...