How to validate SSCC codes, check digit algorithm, EDIFACT extraction and free API

After 18 years working with EDI and supply chain systems, I've lost count of how many times I've had to validate an SSCC, Serial Shipping Container Code. Every time, it was either a one-off script, a colleague with a spreadsheet, or a paid tool hidden behind a login wall. So I built SSCC Pro Vision, a free, open-source validator that runs entirely in the browser. No backend, no login, no cost. And while I was at it, I wrote up everything I know about SSCCs. What is an SSCC? The S...