I came to the 9 May seminar because our stall had taken one USDC payment and I could not tell my father where the fee was. By the third sitting I could show him the lamport line and keep it out of the fish-price column. The first twenty minutes went quickly past the word slot, and I had to ask Hae-won to say again what a slot is before the fee table sat still. After that the morning was clear.
Reader notes
What people wrote after they sat
These notes name a sitting, a constraint, and an outcome. They were written for the day book and are published with permission.
Jun-ho read the March signature with me at the window desk. He would not guess the fee from a cropped screenshot, which cost us ten minutes and saved a wrong line in the cooperative ledger. We booked the ninety minutes and did not need the extra hour.
The counter was too loud, so we moved the refund sentence into the stock room. That was the useful part: staff now say the mint aloud before they nod.
A longer account
The Thursday signature at the dried-seafood stall
In February 2026 the Han stall received USDC from a buyer in Busan who was paying on behalf of a ship chandler. The amount matched the invoice. The card batch from the same week had not cleared. Eun-ji brought the signature on paper to a desk briefing, then brought her father to the May seminar so the vocabulary would be shared.
The constraint was time at the counter. They could not stop the queue for a lesson, so the walkthrough was refused until a Tuesday before opening. Park spent the first hour on where the payer would stand and the four book lines. The test payment was sent by Eun-ji from an address the stall already controlled. The fee sat in SOL. The USDC amount matched the crate price they had written in pencil.
What changed was the book, not the scale. Stablecoin receipts now occupy their own column. Refunds, when a crate is short, leave the next morning with a new signature written under the original. The stall still takes cash and cards. The seminar did not ask them to drop either.