1100 Acrobat PDF/A - Portable Document Format 1b Page Description Full 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. PDF/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. The 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/ Binary 01 Oct 2005 1 Digital Preservation Department / The National Archives 11 Jul 2011 Additional information regarding violations of PDF/A 1b conformance added November 2011. Additional information regarding violations of PDF/A 1b conformance added February 2014. 11 Feb 2022 application/pdf MIME com.adobe.pdf Apple Uniform Type Identifier fmt/354 PUID pdf File extension 521 Acrobat PDF/A 1b 1 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. 1 Absolute from BOF 0 144 255044462D312E[30:37] 1 Variable 786D6C6E733A7064666169643D(22|27)687474703A2F2F7777772E6169696D2E6F72672F706466612F6E732F6964*7064666169643A70617274(3D22|3D27|3E)31(22|27|3C2F7064666169643A706172743E){0-120}7064666169643A636F6E666F726D616E6365(3E|3D22|3D27)42(22|27|3C2F7064666169643A636F6E666F726D616E63653E) 966 Acrobat PDF/A 1b 2 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. 1 Absolute from BOF 0 144 255044462D312E[30:37] 1 Variable 786D6C6E733A7064666169643D(22|27)687474703A2F2F7777772E6169696D2E6F72672F706466612F6E732F6964*7064666169643A636F6E666F726D616E6365(3E|3D22|3D27)42(22|27|3C2F7064666169643A636F6E666F726D616E63653E){0-120}7064666169643A70617274(3D22|3D27|3E)31(22|27|3C2F7064666169643A706172743E) Has lower priority than 818 Acrobat PDF/X - Portable Document Format - Exchange 1a:2001 Has lower priority than 819 Acrobat PDF/X - Portable Document Format - Exchange 3:2002 Has priority over 616 Acrobat PDF 1.3 - Portable Document Format Has priority over 617 Acrobat PDF 1.4 - Portable Document Format Has priority over 618 Acrobat PDF 1.5 - Portable Document Format Has priority over 637 Acrobat PDF 1.6 - Portable Document Format Has priority over 869 TrueType Font Has priority over 1016 Acrobat PDF 1.7 - Portable Document Format