What it actually decides.
A working load limit is the maximum load a manufacturer permits on a shackle, sling, clamp or similar component. It is derived from the breaking strength divided by a design factor, and for most entertainment rigging hardware that factor is five: a component rated at a ton is built to fail somewhere above five tons.
The margin is not slack to be used. It covers wear, shock loading, manufacturing variation, misuse and the fact that nobody knows exactly what a load weighs. Working at the limit consumes it.
Over people the practice is stricter. The North American convention is to halve the published working load limit for anything suspended or moved above an audience or a crew — an effective factor of ten. It is worth being precise about the status of that number, because it is often quoted as law and is not. Some jurisdictions do require it outright. United States occupational regulation and the published event rigging standard do not state a numeric figure; they require instead that loads be calculated, that dynamic forces be accounted for, and that the calculations be documented and available. Halving the WLL is the professional practice that satisfies that requirement, not a rule somebody can be cited under.
The other half is condition. A rated component with a stretched eye, a bent pin or an abraded sling is no longer rated, and the inspection before it goes up is the only point at which that gets noticed.
We own this equipment.
Staging and rigging — owned inventory, our own crew, and a site survey before anything is specified.