{"ok":true,"kind":"crawlcheck-rulebook","v":1,"generated_at":"2026-10-07T17:43:58.097Z","score_version":28,"schema":"https://crawlcheck.io/schemas/rulebook.json","counts":{"rules":77,"by_kind":{"scan":52,"answer_correlation":5,"capability_mismatch":6,"self_audit":12,"mcp_server":2},"by_family":{"site":8,"headers":4,"mostly_code":3,"machine_files":11,"robots":13,"delivery":8,"jsonld":3,"nap":2,"answers":5,"capabilities":6,"self_audit":12,"mcp":1,"watch":1},"revised":7,"scored":48},"scans_counted":3137,"severity_scale":[{"level":"info"},{"level":"low"},{"level":"medium"},{"level":"high"},{"level":"critical"}],"method":{"revisions":"A rule that changes what it reports gets a new revision; a record keeps the revision that decided it, and a replay uses that revision, never today's.","share":"Share of counted scans that carried the code at least once, the same numbers /data publishes. Self-scans and opted-out sites are never counted.","grade":"Each finding has a level from info to critical. Open findings at medium and above lower the letter grade; fix them first."},"rules":[{"code":"AI_OPTOUT_SET","kind":"scan","family":{"id":"robots","label":"Robots"},"title":"An AI opt-out signal is set","meaning":"A Content-Signal directive is telling AI systems not to use this site. CDNs inject this by default on some plans, so it is frequently set without the owner deciding to set it.","severity":{"level":"medium"},"scored":true,"measured_on":"every scan","revision":{"current":1,"revised_at":null},"fix":{"advice":"This is a choice, not a defect. If you want answer engines to quote the site, remove the AI opt-out directives; if you do not, leave it.","effort":"config","endpoint":null},"share_of_scans":{"pct":5,"scans":156,"of_scans":3137,"basis":"share of counted scans that carried it; the same numbers /data publishes"},"links":{"self":"https://crawlcheck.io/rules#AI_OPTOUT_SET","api":"https://crawlcheck.io/api/rules?code=AI_OPTOUT_SET","glossary":["https://crawlcheck.io/glossary/ai-opt-out","https://crawlcheck.io/glossary/machine-readable-opt-out"],"workflow":null,"lineage":"https://crawlcheck.io/docs/lineage-coverage","explain_template":"https://crawlcheck.io/api/explain?id={report_id}&code=AI_OPTOUT_SET"}}],"filter":{"code":"AI_OPTOUT_SET"}}