Reference
Precise contracts, for when the guides have given you the model and you now need the exact rules. These pages are meant to be linkable, stable and boring.
SDA reference
The shaping language used by @shape and sda(...): value model, selectors, projection, comprehensions, predicates and pipes.
In the repository
The full normative specification suite (manifest, HTTP effects, sessions, capabilities, build, deployment, security) lives under docs/specs/. These reference pages summarise the parts an application author touches directly.