A card batch and a USDC transfer do not close on the same clock
How a Seosan counter can tell a card-batch cutoff from a confirmed USDC payment on Solana, using the fields the reading room prints.
Journal
Notes from the shelf
Short pieces on the difference between a card batch and a USDC transfer, the fields of a Solana payment, and the order of the reading room itself.
How to read a Solana payment without losing the plot
Signature, slot, lamports, mint, and memo: the five fields a bookkeeper in the reading room is asked to find before anything else.
Questions worth asking before a stablecoin reaches the counter
Four questions the shop-floor visit puts to an owner in Seosan-si before any test payment is sent.
Why the shelves run from fee tables to a short glossary
Shelf A through shelf D in the Unsan-myeon reading room, and why the glossary sits last rather than first.