{
  "fileFormatID": 1100,
  "formatName": "Acrobat PDF/A - Portable Document Format",
  "version": "1b",
  "formatDescription": "The Portable Document Format/ Archive is a format designed for long term preservation by Adobe Systems. PDF/A is a simplified version of PDF 1.4, with all of the features from PDF 1.4 that would impede long term preservation removed. Removed features include Javascript, Audio/Visual content, LZW compression and encryption. A major principle of PDF/A is that it is self contained and not reliant on externalities thus all font and colour information is encoded into the file. PDF/A files are larger than other types of PDF files due to the need for embedded information.\r\nPDF/A supports two levels of compliance PDF/A1-a (Accessible) and PDF/A1-b (Basic). PDF/A1-a is fully ISO 19005-1:2005 (PDF/A-1) compliant whereas PDF/A1-b is less stringent and not compliant. PDF/A1-a requires tagged PDF and Unicode whereas PDF/A1-b does not.\r\nThe signature identification proposed for PDF/A 1b has been tested against a number of PDF/A and PDF files for verification. However, PDF itself is a complex format, and while the PDF/A 1b signature contained in PRONOM will identify many PDF/A 1b files, DROID can only identify what a file asserts itself to be. As there are a number of ways in which PDF/A 1b files can violate the PDF/A 1b conformance, which can not be spotted until the file is parsed, it is recommended that PDF files are tested against validation software when attempting to confirm identification. Further information concerning PDF/A violations, and a test suite of PDF items which fail to conform to PDF/A standards, can be found at http://www.pdfa.org/2011/08/isartor-test-suite/",
  "releaseDate": "01 Oct 2005",
  "binaryFileFormat": "Binary",
  "formatNote": null,
  "lastUpdatedDate": "11 Feb 2022",
  "formatProvenance": "Additional information regarding violations of PDF/A 1b conformance added November 2011.\r\nAdditional information regarding violations of PDF/A 1b conformance added February 2014.",
  "formatSourceDate": "11 Jul 2011",
  "formatDisclosure": "Full",
  "formatEnvironment": null,
  "formatRisk": null,
  "formatAliases": null,
  "formatTypes": "Page Description",
  "formatFamilies": null,
  "identifiers": [
    {
      "identifierText": "application/pdf",
      "identifierType": "MIME"
    },
    {
      "identifierText": "com.adobe.pdf",
      "identifierType": "Apple Uniform Type Identifier"
    },
    {
      "identifierText": "fmt/354",
      "identifierType": "PUID"
    }
  ],
  "internalSignatures": [
    {
      "signatureID": 521,
      "name": "Acrobat PDF/A 1b 1",
      "note": "Describes a signature for the PDF/A format with 1b conformance. Identifies the PDF header (1.3 through to 1.7) and byte sequence which equals - xmlns:pdfaid=\"http://www.aiim.org/pdfa/ns/id/\">.<pdfaid:part>1</pdfaid:part>.<pdfaid:conformance>B</pdfaid:conformance>. Which is the PDF/A identification namespace within the PDF/A meta-data, and the 1b conformance. See ISO 19005-1:2005 and Technical Corrigendum 1 for further information.",
      "byteSequences": [
        {
          "positionType": "Absolute from BOF",
          "offset": 0,
          "maxOffset": 144,
          "byteSequence": "255044462D312E[30:37]",
          "endianness": null,
          "byteSequenceID": 642
        },
        {
          "positionType": "Variable",
          "offset": null,
          "maxOffset": null,
          "byteSequence": "786D6C6E733A7064666169643D(22|27)687474703A2F2F7777772E6169696D2E6F72672F706466612F6E732F6964*7064666169643A70617274(3D22|3D27|3E)31(22|27|3C2F7064666169643A706172743E){0-120}7064666169643A636F6E666F726D616E6365(3E|3D22|3D27)42(22|27|3C2F7064666169643A636F6E666F726D616E63653E)",
          "endianness": null,
          "byteSequenceID": 643
        }
      ],
      "provenance": "Ongoing DROID research following request from Archaeology Data Service. Signature further refined Nov 2011 with additional EOF sequence in order to avoid misidentifying some PDF/A's which contain 1b conformance declaration, but which are invalid as PDF/A 1b's."
    },
    {
      "signatureID": 966,
      "name": "Acrobat PDF/A 1b 2",
      "note": "Describes a signature for the PDF/A format with 1b conformance. Identifies the PDF header (1.3 through to 1.7) and byte sequence which equals - xmlns:pdfaid=\"http://www.aiim.org/pdfa/ns/id/\">.<pdfaid:conformance>B</pdfaid:conformance>.<pdfaid:part>1</pdfaid:part>. Which is the PDF/A identification namespace within the PDF/A meta-data, and the 1b conformance. See ISO 19005-1:2005 and Technical Corrigendum 1 for further information.",
      "byteSequences": [
        {
          "positionType": "Absolute from BOF",
          "offset": 0,
          "maxOffset": 144,
          "byteSequence": "255044462D312E[30:37]",
          "endianness": null,
          "byteSequenceID": 1186
        },
        {
          "positionType": "Variable",
          "offset": null,
          "maxOffset": null,
          "byteSequence": "786D6C6E733A7064666169643D(22|27)687474703A2F2F7777772E6169696D2E6F72672F706466612F6E732F6964*7064666169643A636F6E666F726D616E6365(3E|3D22|3D27)42(22|27|3C2F7064666169643A636F6E666F726D616E63653E){0-120}7064666169643A70617274(3D22|3D27|3E)31(22|27|3C2F7064666169643A706172743E)",
          "endianness": null,
          "byteSequenceID": 1187
        }
      ],
      "provenance": "Ongoing DROID research following request from Antonio Dalvit. Signature further refined Feb 2014 to allow variations in the additional byte sequence order, in order to avoid misidentifying some PDF/A's which contain 1b conformance declaration as PDF's."
    }
  ],
  "externalSignatures": [
    {
      "externalSignature": "pdf",
      "signatureType": "File extension"
    }
  ],
  "relationships": [
    {
      "relationshipType": "Has lower priority than",
      "relatedFormatID": 818,
      "relatedFormatName": "Acrobat PDF/X - Portable Document Format - Exchange 1a:2001",
      "relatedFormatPUID": "fmt/157"
    },
    {
      "relationshipType": "Has lower priority than",
      "relatedFormatID": 819,
      "relatedFormatName": "Acrobat PDF/X - Portable Document Format - Exchange 3:2002",
      "relatedFormatPUID": "fmt/158"
    },
    {
      "relationshipType": "Has priority over",
      "relatedFormatID": 616,
      "relatedFormatName": "Acrobat PDF 1.3 - Portable Document Format",
      "relatedFormatPUID": "fmt/17"
    },
    {
      "relationshipType": "Has priority over",
      "relatedFormatID": 617,
      "relatedFormatName": "Acrobat PDF 1.4 - Portable Document Format",
      "relatedFormatPUID": "fmt/18"
    },
    {
      "relationshipType": "Has priority over",
      "relatedFormatID": 618,
      "relatedFormatName": "Acrobat PDF 1.5 - Portable Document Format",
      "relatedFormatPUID": "fmt/19"
    },
    {
      "relationshipType": "Has priority over",
      "relatedFormatID": 637,
      "relatedFormatName": "Acrobat PDF 1.6 - Portable Document Format",
      "relatedFormatPUID": "fmt/20"
    },
    {
      "relationshipType": "Has priority over",
      "relatedFormatID": 869,
      "relatedFormatName": "TrueType Font",
      "relatedFormatPUID": "x-fmt/453"
    },
    {
      "relationshipType": "Has priority over",
      "relatedFormatID": 1016,
      "relatedFormatName": "Acrobat PDF 1.7 - Portable Document Format",
      "relatedFormatPUID": "fmt/276"
    }
  ],
  "submittedBy": [
    1
  ]
}