Ring order is the running order — lot with the lowest ring order sells first, then the next, and so on. It is independent of the lot number, so you can re-sequence the sale (move a hot lot up, hold a problem lot back) without renumbering anything.
Reordering the sale changes ring order, not lot numbers. Buyers and consignors still recognize their animals by lot number even if the run order shifts.
Technical section
Data model, API, and internals — visible to developers.