I wish they went into some of the more exotic 2d codes. I found a weird sort of 2d code that consisted of concentric circles with data bits encoded as circular dots along each "track". It was like a weird mix between a Vinyl record and a computer punch card. I've also seen triangular and hex grids used in some encodings. My favorite is the ones that triple the information density by simply printing a different QR code in the red, green, and blue channel (all on top of each other obviously).

I'm never quite sure why some businesses choose to implement these non-standard solutions. Is it a form of vendor lock in? Do they just want something with less of a digital-brutalism aesthetic? Is it an attempt at security through obscurity? All of the above?

The article is only half right about laser scanners and the ability to read 2d codes. In principle it wouldn't be too hard to engineer a laser pattern / data matrix pattern that works. The trivial solution is to just make the laser run in scan lines like an old analog TV, but then the person doing the scan needs to be annoyingly precise in how they point the scanner at the data. If digital cameras and image processing weren't dirt cheap, there would still be visible spectrum 2d data encodings.