Spec
The document that briefs the builder: what to build, the evaluations, the verifications, and what done has to clear.
A spec is the document that holds everything a request needs to get built. When work moves from deciding to building, this is what travels. Mine follow the same shape: a brief on what needs to be done and why, the approach the evidence supports, and the sections that matter most, the evaluations and the verifications: how the result gets checked, and what it has to clear before anyone calls it done.
What a spec leaves out matters as much as what it holds. It stays quiet on the hundred implementation choices that belong to whoever builds it, so the builder is free to propose a better approach and both sides have a fixed thing to argue against. When I say a build went from spec to shipped, the spec is the reason we agree on what shipped means.