A requirement the spck.dev suite checks on UCP servers. The quoted text is the normative requirement; the citation links to the exact line of the pinned spec source it was taken from.
`continue_to` is untrusted input: a Business MUST validate it server-side by percent-decoding once, rejecting unless it starts with a single `/` (not `//`) and contains no scheme/backslash/whitespace/control character, resolving it against the endpoint's origin, and rejecting unless the result is same-origin
A deviation on a MUST fails the run and shows the requirement next to the actual response. Checks the suite cannot validate soundly are reported inconclusive or not-tested — never a silent pass. The full verdict semantics are on the grading rubric.
The hosted check covers the read-only surface; the CLI and GitHub Action run the full suite, including this check when your store declares the capability it belongs to.