Fable
The register at the city gate that only recognized numbers
Lighthouse Town had an old sorting machine. It did not look at the whole letter, only at the number on the wooden chip. Each number corresponded to a character block in the roster, and the gatekeeper fed the wooden chips into the machine by number.
In earlier years, few letters came to the town, and the roster was enough. Later, outside caravans brought new place names, new goods names, and new surnames. The gatekeeper could not find matching numbers, so he had to split unfamiliar words into scattered wooden pieces. The sorting machine could read them, but often cut the meaning in very strange ways.
The mayor first had the gatekeeper assign temporary numbers. A few days later, the same place name was numbered into three different sets by three people, and old letters no longer matched new ones. The second fix was to add all new terms as whole blocks into the register. The register quickly ballooned, and commonly used numbers were squeezed into disorder.
The old clerk revised the roster: common character blocks kept stable numbers, new words had to be registered, overly rare words were split according to rules, and common new words were later promoted to independent entries. The roster could be neither too small nor arbitrarily expanded.
The new rules made the sorting machine much more stable. When it encountered an unfamiliar goods name, it could process it by known character blocks; when a high-frequency new word appeared, the register would formally include it. The gatekeeper also knew that once an ID changed, many previously accumulated correspondences would be affected.
Lighthouse Town finally understood that the roster was not an ordinary dictionary, but a boundary that cut text into processable units and assigned numbers. It determined which character blocks the machine could see, how inputs were combined, and in what form unfamiliar words entered the system.
The old clerk also kept old versions of the roster. If the new roster changed the segmentation method, past letters needed to know which version was used at the time, otherwise old and new numbering would be misaligned. The roster seems basic, yet it affects the entire processing order.
Later, when Lighthouse Town trained newcomers, they did not first talk about how smart the machine was, but had them cut several out-of-town letters by hand. Cut too finely, and the meaning scattered; cut too coarsely, and the roster could not hold it. The right vocabulary was a trade-off among expressiveness, stability, and scale. Later, as more new out-of-town words appeared, the roster was also updated regularly. Before each update, the clerk would test whether old letters could still be correctly fed into the machine. A roster that can steadily carry change is the sorter's true entrance. If the roster is stable, later processing will not fall apart at the first step. Later, each time a new character block was added, the clerk would ask whether it was common enough and whether it would break the old numbering.