Glossary
At-once vs futures orders: what is the difference?
At-once vs futures: An at-once order ships from inventory the brand has available now; a futures order (also called a pre-book or booking) reserves product for a later delivery window, often months ahead, usually at season-planning time.
In a Bridge to Brands availability grid, the at-once row has date: null and ordering_mode: "at_once"; each future delivery window is its own row with a date and ordering_mode: "future". Order lines can name the mode explicitly with ordering_mode.