Daily reset

The board wipes on a fixed boundary, usually midnight UTC. Yesterday’s spend buys nothing today, which means the operator can sell the same top spot 365 times a year rather than once.

It also solves the problem every permanent board eventually has: once someone pays enough to hold #1 forever, there is nothing left to sell.

Boards are filed under this rule when their own copy matches a published phrase list. The matched phrase is printed in each board’s evidence ledger, so the classification can be checked rather than taken on faith.