{
 "metric": "tls-legacy",
 "segment": "gb-companies",
 "anchor": "company",
 "label": "UK companies",
 "population": "UK companies",
 "states": [
  "modern_only",
  "legacy_enabled"
 ],
 "quiet_failure_states": [
  "legacy_enabled"
 ],
 "measurement": "Tier 2, via the DomainAPI TLS endpoint, which tests each protocol version explicitly. Denominator: `has_web`.",
 "why_it_matters": "Supporting a deprecated protocol version is invisible from the browser — the site loads over TLS 1.3 and looks modern — while the server remains willing to downgrade for anything that asks.",
 "limits": "Must be measured server-side. A modern client cannot detect this, because its own OpenSSL refuses to *offer* TLS 1.0/1.1.",
 "data_tier": "tls",
 "population_predicate": "has_web",
 "entity_type": "domain",
 "kind": "failure",
 "latest": {
  "day": "2026-08-13",
  "n": 1974,
  "qf_pct": 11.3,
  "ci": [
   9.97,
   12.77
  ],
  "dist": {
   "modern_only": 88.7,
   "legacy_enabled": 11.3
  },
  "snapshot": "uk-companies-house-per600-seed20260728"
 },
 "series": [
  {
   "day": "2026-08-06",
   "n": 1971,
   "qf_pct": 11.21,
   "ci": [
    9.89,
    12.68
   ],
   "dist": {
    "modern_only": 88.79,
    "legacy_enabled": 11.21
   },
   "snapshot": "uk-companies-house-per600-seed20260728"
  },
  {
   "day": "2026-08-13",
   "n": 1974,
   "qf_pct": 11.3,
   "ci": [
    9.97,
    12.77
   ],
   "dist": {
    "modern_only": 88.7,
    "legacy_enabled": 11.3
   },
   "snapshot": "uk-companies-house-per600-seed20260728"
  }
 ],
 "license": "CC BY 4.0",
 "source": "https://quietfailures.com/datasets/tls-legacy/gb-companies"
}