Why dots instead of squares
DotCode encodes data in isolated dots placed on alternate positions of a grid, so no two dots need to touch. High-speed industrial inkjet and laser printers are good at placing individual dots but struggle to print solid, joined squares cleanly at line speed, and DotCode is designed around that.
The symbol has no fixed finder pattern like the corners of a QR code; the reader recognizes the dot grid itself. Its width and height can be chosen flexibly, which suits long, low print areas.
Standards and uses
DotCode is published by AIM as the ISS DotCode symbology specification rather than as an ISO/IEC standard. It can carry GS1 data, including GTINs and serial numbers.
It is used for marking packs at very high speed, notably in tobacco traceability, where the EU rules allow it among the permitted data carriers, and on some pharmaceutical and beverage lines. It is an industrial format; consumer phone cameras generally do not read it.