{
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  "lastModified": "2026-10-13T17:53:39.161Z",
  "sourcePath": "src/main/data/docs",
  "docId": "RFC4821",
  "document": {
    "abstract": "This document describes a robust method for Path MTU Discovery (PMTUD) that relies on TCP or some other Packetization Layer to probe an Internet path with progressively larger packets. This method is described as an extension to RFC 1191 and RFC 1981, which specify ICMP-based Path MTU Discovery for IP versions 4 and 6, respectively. [STANDARDS-TRACK]",
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      "confidence": "high",
      "note": "Parsed from RFC index XML abstract",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "authors": [
      {
        "name": "Matt Mathis"
      },
      {
        "name": "John Heffner"
      }
    ],
    "authors$meta": {
      "confidence": "high",
      "note": "Parsed from Datatracker doc page article:author (profile full names)",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "docId": "RFC4821",
    "docId$meta": {
      "confidence": "high",
      "note": "Derived from RFC number or Datatracker identifier",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "docLabel": "IETF RFC 4821",
    "docLabel$meta": {
      "confidence": "high",
      "note": "Constructed from provider and document identifier",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "docNumber": "4821",
    "docNumber$meta": {
      "confidence": "high",
      "note": "Parsed from RFC info page report metadata",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "docTitle": "Packetization Layer Path MTU Discovery",
    "docTitle$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML title",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "docType": "Standard",
    "docType$meta": {
      "confidence": "high",
      "note": "Mapped from Datatracker std_level or RFC status text",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "doi": "10.17487/RFC4821",
    "doi$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML doi",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "href": "https://doi.org/10.17487/RFC4821",
    "href$meta": {
      "confidence": "high",
      "note": "Derived from DOI (https://doi.org/<doi>)",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "keywords": [
      "MTU",
      "PMTUD"
    ],
    "keywords$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML keywords",
      "originalValue": [
        "MTU",
        "Pmtud"
      ],
      "overridden": true,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:53:39.161Z",
      "version": "extractDocs.js@commit:25936397c06b"
    },
    "pages": "32",
    "pages$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML page-count",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "publicationDate": "2007-03-01",
    "publicationDate$meta": {
      "confidence": "high",
      "note": "Parsed from RFC index XML date",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "publisher": "IETF",
    "publisher$meta": {
      "confidence": "high",
      "note": "Static: provider",
      "originalValue": null,
      "source": "parsed",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "references": {
      "bibliographic": [
        "RFC2760",
        "RFC1122",
        "RFC2923",
        "RFC2401",
        "RFC2914",
        "RFC2461",
        "RFC3517",
        "RFC4340",
        "orphan/RFC4821/h:01d67728",
        "orphan/RFC4821/h:54b14bdd",
        "orphan/RFC4821/h:feee2b18"
      ],
      "bibliographic$meta": {
        "confidence": "medium",
        "flag": "MIXED_REF_LAYOUT_RISK anchored=20 proseBlocks=29 skippedAnchorBlocks=23",
        "note": "Parsed from RFC HTML references/informative sections",
        "originalValue": [],
        "reviewRequired": true,
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
        "updated": "2026-10-13T17:23:40.611Z",
        "version": "extractDocs.js@commit:996495349225"
      },
      "normative": [
        "RFC791",
        "RFC1191",
        "RFC1981",
        "RFC2119",
        "RFC2460",
        "RFC793",
        "RFC3697",
        "RFC2960",
        "RFC4820"
      ],
      "normative$meta": {
        "confidence": "high",
        "note": "Parsed from RFC HTML normative references sections",
        "originalValue": [],
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
        "updated": "2026-10-13T17:23:40.611Z",
        "version": "extractDocs.js@commit:996495349225"
      }
    },
    "resolvedHref": "https://www.rfc-editor.org/info/rfc4821/",
    "resolvedHref$meta": {
      "confidence": "high",
      "note": "Final URL resolved via URL redirect verification",
      "originalValue": null,
      "source": "resolved",
      "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
      "updated": "2026-10-13T17:23:40.611Z",
      "version": "extractDocs.js@commit:996495349225"
    },
    "status": {
      "active": true,
      "active$meta": {
        "confidence": "high",
        "note": "Derived from supersession relationship fields",
        "originalValue": null,
        "source": "resolved",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
        "updated": "2026-10-13T17:23:40.611Z",
        "version": "extractDocs.js@commit:996495349225"
      },
      "amendedBy": [
        "RFC8899"
      ],
      "amendedBy$meta": {
        "confidence": "high",
        "note": "Parsed from RFC index XML",
        "originalValue": [],
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
        "updated": "2026-10-13T17:23:40.611Z",
        "version": "extractDocs.js@commit:996495349225"
      },
      "errataExist": false,
      "errataExist$meta": {
        "confidence": "high",
        "note": "Derived from presence of errata links on RFC/Datatracker pages",
        "originalValue": null,
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
        "updated": "2026-10-13T17:23:40.611Z",
        "version": "extractDocs.js@commit:996495349225"
      },
      "latestVersion": true,
      "latestVersion$meta": {
        "confidence": "high",
        "note": "Derived from supersession relationship fields",
        "originalValue": null,
        "source": "resolved",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
        "updated": "2026-10-13T17:23:40.611Z",
        "version": "extractDocs.js@commit:996495349225"
      },
      "statusNote": "Proposed Standard",
      "statusNote$meta": {
        "confidence": "high",
        "note": "Mapped from Datatracker doc.json std_level",
        "originalValue": null,
        "source": "parsed",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
        "updated": "2026-10-13T17:23:40.611Z",
        "version": "extractDocs.js@commit:996495349225"
      },
      "superseded": false,
      "superseded$meta": {
        "confidence": "high",
        "note": "Derived from supersession relationship fields",
        "originalValue": null,
        "source": "resolved",
        "sourceUrl": "https://www.rfc-editor.org/info/rfc4821/",
        "updated": "2026-10-13T17:23:40.611Z",
        "version": "extractDocs.js@commit:996495349225"
      }
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}