{
  "registry": "HTML&HTML External Evidence Source Registry",
  "version": "1.3.0",
  "lastVerified": "2026-09-13",
  "policy": "External behavior claims must point to a first-party vendor, standards body or clearly labeled proposal source. Availability monitoring does not prove semantic stability; material rule changes require human review and a profile version decision. Industry terminology and HTML&HTML heuristics must never be represented as Google ranking systems.",
  "sources": [
    {
      "id": "RFC9309",
      "class": "OFFICIAL_STANDARD",
      "publisher": "IETF / RFC Editor",
      "title": "Robots Exclusion Protocol",
      "url": "https://www.rfc-editor.org/rfc/rfc9309.html",
      "appliesTo": [
        "crawl",
        "ai",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "OPENAI-SEARCH",
      "class": "OFFICIAL_VENDOR",
      "publisher": "OpenAI",
      "title": "Searching the web with ChatGPT",
      "url": "https://help.openai.com/en/articles/9237897",
      "appliesTo": [
        "ai"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "OPENAI-PUBLISHERS",
      "class": "OFFICIAL_VENDOR",
      "publisher": "OpenAI",
      "title": "Publishers and Developers FAQ",
      "url": "https://help.openai.com/en/articles/12627856-publishers-and-developers-faq",
      "appliesTo": [
        "ai",
        "glossary"
      ],
      "lastVerified": "2026-09-09"
    },
    {
      "id": "OPENAI-RESPONSES-WEBSEARCH",
      "class": "OFFICIAL_VENDOR",
      "publisher": "OpenAI",
      "title": "OpenAI API quickstart — Responses API with web search",
      "url": "https://platform.openai.com/docs/quickstart/make-your-first-api-request",
      "appliesTo": [
        "ai",
        "mention",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "ANTHROPIC-CRAWLERS",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Anthropic",
      "title": "Anthropic web crawlers and site-owner controls",
      "url": "https://support.anthropic.com/en/articles/8896518-does-anthropic-crawl-data-from-the-web-and-how-can-site-owners-block-the-crawler",
      "appliesTo": [
        "ai"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "PERPLEXITY-ROBOTS",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Perplexity",
      "title": "How does Perplexity follow robots.txt?",
      "url": "https://www.perplexity.ai/help-center/en/articles/10354969-how-does-perplexity-follow-robots-txt",
      "appliesTo": [
        "ai"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "PERPLEXITY-SONAR",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Perplexity",
      "title": "Sonar API — Create Chat Completion",
      "url": "https://docs.perplexity.ai/api-reference/sonar-post",
      "appliesTo": [
        "ai",
        "mention",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-COMMON-CRAWLERS",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google",
      "title": "Google's common crawlers",
      "url": "https://developers.google.com/crawling/docs/crawlers-fetchers/google-common-crawlers",
      "appliesTo": [
        "crawl",
        "ai",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-AI-OPTIMIZATION",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Google's Guide to Optimizing for Generative AI Features on Google Search",
      "url": "https://developers.google.com/search/docs/fundamentals/ai-optimization-guide",
      "appliesTo": [
        "seo",
        "ai",
        "geo",
        "aeo",
        "rag",
        "agent",
        "glossary"
      ],
      "lastVerified": "2026-09-09"
    },
    {
      "id": "GOOGLE-AI-FEATURES",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "AI Features and Your Website",
      "url": "https://developers.google.com/search/docs/appearance/ai-features",
      "appliesTo": [
        "seo",
        "ai",
        "crawl",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-SEARCH-ESSENTIALS",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Google Search Essentials",
      "url": "https://developers.google.com/search/docs/essentials",
      "appliesTo": [
        "seo",
        "crawl",
        "trust",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-HELPFUL-CONTENT",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Creating Helpful, Reliable, People-First Content",
      "url": "https://developers.google.com/search/docs/fundamentals/creating-helpful-content",
      "appliesTo": [
        "seo",
        "trust",
        "eeat",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-SITEMAPS",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Build and Submit a Sitemap",
      "url": "https://developers.google.com/search/docs/crawling-indexing/sitemaps/build-sitemap",
      "appliesTo": [
        "crawl",
        "technical",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-CANONICAL",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Canonicalization and Consolidating Duplicate URLs",
      "url": "https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls",
      "appliesTo": [
        "technical",
        "crawl",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-STRUCTURED-DATA",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Search Appearance and Structured Data",
      "url": "https://developers.google.com/search/docs/appearance",
      "appliesTo": [
        "schema",
        "seo",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-ORGANIZATION-SCHEMA",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Organization Structured Data",
      "url": "https://developers.google.com/search/docs/appearance/structured-data/organization",
      "appliesTo": [
        "schema",
        "trust",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-INTERNATIONAL",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Managing Multi-Regional and Multilingual Sites",
      "url": "https://developers.google.com/search/docs/specialty/international/managing-multi-regional-sites",
      "appliesTo": [
        "technical",
        "seo",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-PREFERRED-SOURCES",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Guide to Preferred Sources in Google Search for Web Publishers",
      "url": "https://developers.google.com/search/docs/appearance/preferred-sources",
      "appliesTo": [
        "ai",
        "seo",
        "glossary"
      ],
      "lastVerified": "2026-09-10"
    },
    {
      "id": "GOOGLE-REGIONAL-SEARCH",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Regional differences in Search experience",
      "url": "https://developers.google.com/search/docs/appearance/aggregator-features",
      "appliesTo": [
        "seo",
        "schema",
        "geo",
        "crawl",
        "glossary"
      ],
      "lastVerified": "2026-09-09"
    },
    {
      "id": "GOOGLE-THIRD-PARTY-SEO",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Google Search's Guidance on Third-Party SEO Tools & Advice",
      "url": "https://developers.google.com/search/docs/fundamentals/third-party-seo",
      "appliesTo": [
        "seo",
        "ai",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-DEVELOPER-SEO",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "SEO Guide for Web Developers",
      "url": "https://developers.google.com/search/docs/fundamentals/get-started-developers",
      "appliesTo": [
        "technical",
        "crawl",
        "seo",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-SEARCH-UPDATES-2026",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Latest Google Search Documentation Updates",
      "url": "https://developers.google.com/search/updates",
      "appliesTo": [
        "seo",
        "ai",
        "llms",
        "glossary"
      ],
      "lastVerified": "2026-09-09"
    },
    {
      "id": "GEMINI-GOOGLE-SEARCH",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google AI for Developers",
      "title": "Gemini API — Grounding with Google Search",
      "url": "https://ai.google.dev/gemini-api/docs/google-search",
      "appliesTo": [
        "ai",
        "mention",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "LLMS-TXT-V2",
      "class": "PROPOSAL",
      "publisher": "llmstxt.org / Jeremy Howard",
      "title": "The /llms.txt file, v2",
      "url": "https://llmstxt.org/",
      "appliesTo": [
        "llms",
        "agent",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "LLMS-TXT-CHANGES",
      "class": "PROPOSAL",
      "publisher": "llmstxt.org / Jeremy Howard",
      "title": "llms.txt changes — v2",
      "url": "https://llmstxt.org/changes.html",
      "appliesTo": [
        "llms",
        "agent",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "WCAG22",
      "class": "OFFICIAL_STANDARD",
      "publisher": "W3C",
      "title": "Web Content Accessibility Guidelines (WCAG) 2.2",
      "url": "https://www.w3.org/TR/WCAG22/",
      "appliesTo": [
        "accessibility",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "OPENAPI31",
      "class": "OFFICIAL_STANDARD",
      "publisher": "OpenAPI Initiative",
      "title": "OpenAPI Specification 3.1",
      "url": "https://spec.openapis.org/oas/v3.1.0.html",
      "appliesTo": [
        "agent",
        "glossary"
      ],
      "lastVerified": "2026-09-06"
    },
    {
      "id": "GOOGLE-FAQ-RICH-RESULT-REMOVAL",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Google Search documentation update — FAQ rich results removed",
      "url": "https://developers.google.com/search/updates",
      "appliesTo": [
        "aeo",
        "schema",
        "seo",
        "glossary"
      ],
      "lastVerified": "2026-09-09",
      "note": "FAQ rich results were removed from Google Search in May 2026; question/answer structure may still aid readability but must not be scored as FAQ rich-result eligibility."
    },
    {
      "id": "GOOGLE-LLMS-TXT-CLARIFICATION",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Google Search documentation update — llms.txt clarification",
      "url": "https://developers.google.com/search/updates",
      "appliesTo": [
        "llms",
        "seo",
        "geo",
        "glossary"
      ],
      "lastVerified": "2026-09-09",
      "note": "Google states llms.txt is not needed for Google Search and does not positively or negatively affect visibility or rankings."
    },
    {
      "id": "GOOGLE-GENAI-PERFORMANCE-2026",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Introducing Search Generative AI performance reports in Search Console",
      "url": "https://developers.google.com/search/blog/2026/06/gen-ai-performance-reports",
      "appliesTo": [
        "seo",
        "geo",
        "ai",
        "measurement",
        "search-console"
      ],
      "lastVerified": "2026-09-09"
    },
    {
      "id": "MS-CLARITY-AI-VISIBILITY-2026",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Microsoft Clarity",
      "title": "Microsoft Clarity AI Visibility and Citations Overview (Page citations, Share of authority, AI referral traffic, Grounding queries)",
      "url": "https://learn.microsoft.com/en-us/clarity/ai-visibility/citations-overview",
      "appliesTo": [
        "ai",
        "citations",
        "telemetry",
        "grounding-queries",
        "share-of-authority",
        "clarity"
      ],
      "lastVerified": "2026-09-08"
    },
    {
      "id": "GOOGLE-VIDEO-STRUCTURED-DATA",
      "class": "OFFICIAL_VENDOR",
      "publisher": "Google Search Central",
      "title": "Video Structured Data (ineligibleRegion Property Specification)",
      "url": "https://developers.google.com/search/docs/appearance/structured-data/video",
      "appliesTo": [
        "schema",
        "seo",
        "crawl-eligibility"
      ],
      "lastVerified": "2026-09-13",
      "note": "Google added official support for ineligibleRegion on VideoObject on September 10, 2026 for region-specific search eligibility."
    }
  ]
}