A payment code replaces guesswork. With it, a bank or app payment can be matched to its order automatically; without it, someone has to compare names and amounts by hand.
Payment code
A short code the buyer puts in a payment note so the payment matches its order.
See it running on your own catalog
Purity does the work these terms describe: batches held until their lab report is in, payments matched to orders, and wording checked before it sends.