A named, human-set scalar value referenced inside a step's command text as a MAconst:Name token. Add one under Admin -> Constants (Name, Type, Value, Fleet-wide vs. Local), then reference it anywhere in a step's command text -- Worker substitutes it right before the step runs, for every step type.

See the full Constants guide for per-step-type escaping rules and what's not built yet (table-shaped values, step-output Variables).

See also: Glossary for related terms.