Technical resources
The following technical resource pages are actively maintained by the PDF Association to provide the PDF industry with the latest technical information.
Contents
- Technical resources
- ISO standards for PDF
- Status of PDF standardization at ISO
- Errata to ISO PDF related standards
- PDF 2.0 normative references
- PDF specification archive
- PDF Association Technical Working Groups
- GitHub repositories
- Upcoming and recent events
- PDF Association technical publications
- Flyers and booklets
- Test suites and protocols
ISO standards for PDF
The index of all published ISO standards related to PDF provides a mapping between ISO document numbers and the PDF nomenclature commonly used in industry (such as PDF/A, PDF/X, XMP, etc).
Status of PDF standardization at ISO
This resource summarizes the active and ongoing work items of all ISO committees dedicated to standardizing PDF. ISO Technical Committee (TC) 171 SC 2 Working Groups (WGs) are responsible for many PDF-related ISO publications. ISO TC 130 WG 2 and related Task Forces (TFs) are responsible for PDF/X, PDF/VT, and other PDF-related graphic arts and commercial print applications. ISO TC 130 JWG 7 is the joint working group responsible for ICC and color management.
This resource lists all resolved errata in PDF-related ISO standards. It is presented as localized marked-up changes (additions, deletions, or editor notes) to the published wording in the relevant ISO standard organized by top level clause. Issue numbers (implemented here as popup tooltips) refer back to closed GitHub pdf-issues with a "proposed solution" label. Due to ISO copyright, only minimal surrounding text from the relevant ISO standard is provided that is sufficient to locate where the resolution is being applied.
PDF 2.0 normative references
This resource provides download links for all Normative References of PDF 2.0 (ISO 32000-2:2020). Normative references are other additional standards and specifications where some or all of their content also constitutes technical requirements of PDF 2.0. They form essential reading for all developers of PDF 2.0 technology.
PDF specification archive
This resource provides download links to legacy Adobe PDF references and errata, as well as the full ISO 32000 family of standards. It serves as an archive of the evolution of the core PDF file format.
PDF Association Technical Working Groups
The PDF Association maintains various interest-specific communities facilitating members' discussions on technical issues related to PDF. If your interest is specific to Tagged PDF this article covers the focus on this area.
GitHub repositories
The PDF Association hosts several public and private repositories in GitHub to facilitate a common understanding of PDF and to develop new ideas around PDF technologies. Private repositories are restricted to PDF Association members and support our communities. Public repositories welcome contributions and comments from anyone.
Upcoming and recent events
Every PDF Association event provides a forum for the PDF industry to meet and discuss a broad range of technical topics, challenges and solutions. The videos of previous presentations provide a good body of knowledge.
PDF Association technical publications
The PDF Association provides many technical publications to assist developers and end-users to better utilize standardized PDF technologies. PDF Association publications are qualified and approved through the organization's publication process.
Specifications
PDF Association specifications are industry-ratified specifications that extend PDF.
| Title | Publication Date |
|---|---|
| PDF/Raster 1.0 | July 20, 2017 |
| PDF Declarations | September 5, 2019 |
| Deriving HTML from PDF Version 1.0 | June 11, 2019 |
| Well-Tagged PDF (WTPDF) | February 27, 2024 |
| EA-PDF | February 11, 2025 |
Technical notes
Technical Notes provide additional clarity on the interpretation of ambiguous, unclear or purposely flexible statements in ISO PDF standards.
| Title | Publication Date |
|---|---|
| Technical Note 0001: PDF/A-1 and Namespaces | March 14, 2008 |
| Technical Note 0002: Color in PDF/A-1 | March 14, 2008 |
| Technical Note 0003: Metadata in PDF/A-1 | March 18, 2008 |
| Technical Note 0006: Digital Signatures in PDF/A-1 | March 14, 2008 |
| Technical Note 0008: Predefined XMP Properties in PDF/A-1 | March 20, 2008 |
| Technical Note 0009: XMP Extension Schemas in PDF/A-1 | March 20, 2008 |
| Technical Note 0010: Clarifications of ISO 19005, parts 1-3 for developers of PDF/A creators and validators | July 15, 2017 |
| PDF 1.7 – ISO 32000-1 Summary of Changes | August 1, 2008 |
Cheat sheets
The PDF Association provides free PDF “cheat sheets” to aid in remembering key terms and concepts without constantly referring to ISO 32000. A single download as a PDF collection containing all cheat sheets is also available.
| Cheatsheet Title | Publication Date |
|---|---|
| PDF Basics | October 29, 2024 (updated) |
| Graphic Operators and Operands | October 29, 2024 (updated) |
| Common Objects | October 29, 2024 (updated) |
| Color | October 29, 2024 (updated) |
| Logical structure | October 29, 2024 |
| Standard structure elements | October 29, 2024 |
| Standard structure attributes | October 29, 2024 |
| Math | October 29, 2024 |
| Arlington PDF Model | October 29, 2024 |
Other notes
Adobe's patent release regarding ISO 32000-1:2008 (2011 statement by Adobe's Matthew Hardy).
RFC 8118, "The application/pdf Media Type" (March 2017)
RFC 3779, "The application/pdf Media Type" (May 2004) - obsoleted by RFC 8118.
Application notes & best practice guides
Application Notes provide additional technical information around a specific feature of PDF that enables greater interoperability. Best practice guides offer concrete advice targeting specific outcomes.
| Title | Publication Date |
|---|---|
| Understanding Private Data in PDF/A | June 12, 2024 |
| "A Practical Guide to Implementing and Using the PDF/X-6 Standard: Application Notes for Users and Implementers of PDF/X-6, PDF/X-6p, and PDF/X-6n", prepared by ISO TC 130 WG 2 | September 2022 |
| Best Practice in Creating Print Files for Variable Data Printing - Designer Edition | June 2, 2022 |
| Best Practice in Creating Print Files for Variable Data Printing - Developer Edition | June 2, 2022 |
| PDF 2.0 Application Note 003: Use of object metadata streams | March 16, 2021 |
| PDF 2.0 Application Note 002: Associated Files | October 26, 2018 |
| PDF 2.0 Application Note 001: Black Point Compensation | September 17, 2018 |
| Tagged PDF Best Practice Guide: Syntax | June 10, 2019 |
| PDF/VT Application Notes | January 3, 2016 |
| "Application Notes for PDF/X Standards Version 4 (PDF/X-1a:2003, PDF/X-2:2003 & PDF/X-3:2003)", prepared by ISO TC 130 WG 2 | September 2006 |
Flyers and booklets
The PDF Association publishes numerous flyers, leaflets and booklets in several languages that assist end-users of PDF and their decision-makers to better understand how each PDF ISO standard provides specific benefits to industry sectors.
| Description | Direct Download | Publication Date |
|---|---|---|
| PDF Association Flyer | English English US Letter | May 30, 2019 |
| Promoting ISO Standards for PDF Technology | English US Letter | February, 2018 |
| PDF/A Flyer (PDF/A-1, PDF/A-2, PDF/A-3) | English | June 18, 2015 |
| PDF/UA Flyer (PDF/UA-1) | English | August 1, 2013 |
| PDF/VT Flyer (PDF/VT-1, PDF/VT-2) | English | January 16, 2014 |
| PDF/VT for Personalized Print (flyer) (PDF/VT-1, PDF/VT-2) | English | January 29, 2013 |
| ISO 16612-2 - The PDF Standard for Personalized Print (flyer) (PDF/VT-1, PDF/VT-2) | English | December 2013 |
| PDF/A in a Nutshell 2.0 (PDF/A-1, PDF/A-2, PDF/A-3) | English | May 23, 2013 |
| PDF/A kompakt 2.0 (PDF/A-1, PDF/A-2, PDF/A-3) | Deutsch | May 26, 2009 |
| PDF/A l'essentiell 2.0 (PDF/A-1, PDF/A-2, PDF/A-3) | French | Dec 1, 2014 |
| Introducción al PDF/A (PDF/A-1, PDF/A-2, PDF/A-3) | Español | September 12, 2010 |
| PDF/X in a Nutshell (PDF/X-1, PDF/X-3, PDF/X-4, PDF/X-5) | English | May 15, 2017 |
| PDF/UA in a Nutshell (PDF/UA-1) | English | August 1, 2013 |
| PDF in Manufacturing | English | May 13, 2020 |
| 4th International PDF/A Conference Proceedings | English | October 1, 2010 |
Test suites and protocols
The PDF Association publishes test suites and test protocols to assist both developers and end-users in assessing ISO-compliant PDF technology solutions.
Techniques for Accessible PDF
These Techniques provide authoritative answers to questions on how to make PDF files accessible consistent with both ISO 14289, the international standard for accessible PDF and W3C’s WCAG standard for accessible web content. They consist of vendor-neutral information and example files, allowing PDF files to be precisely tested while ensuring software developers retain maximum flexibility and potential for innovation.
CC-MAIN-2021-31-PDF-UNTRUNCATED
This corpus contains nearly 8 million PDFs gathered from across the web in July/August of 2021. The PDF files were initially identified by Common Crawl as part of their July/August 2021 crawl (identified as "CC-MAIN-2021-31") and, due to truncation at 1MB, were subsequently updated and indexed as part of the PDF Association's DARPA SafeDocs program efforts. It is hosted by the Digital Corpora Project under the Amazon Open Data Sponsorship program.
“Issue Tracker” corpus
The "Issue Tracker" corpus of stressful PDF files was originally developed under the DARPA-funded "SafeDocs" program. If a “stressful PDF” can be considered as any file that causes problems for a parser, then looking into the problems faced by diverse parsers can be a great learning experience. This corpus now includes bug attachment data from 35 issue tracker repositories across 32 PDF technologies, comprising 31 GB and over 32,500 stressful PDF files.
These issue trackers now span a broad variety of PDF technologies written in a wide range of programming languages. Due to the size, we have packaged the corpus into six compressed tarballs (.tgz files) each containing the data from multiple repositories to make downloading more convenient.
Isartor (PDF/A-1)
The Isartor Test Suite comprises a set of files that can be used to check the conformance of software regarding the PDF/A-1 standard. More precisely, the Isartor test suite can be used to “validate the validators” as it deliberately violates the requirements of PDF/A-1 in a systematic way in order to check whether PDF/A-1 validation software actually finds the violations.
veraPDF (PDF/A)
VeraPDF is the industry-supported open-source validator for PDF/A-1, PDF/A-2 and PDF/A-3. The software and related test suite was developed under the supervision of the PDF Association's PDF Validation Technical Working Group.
PDF/UA Reference Suite 1.1
The PDF/UA Reference Suite is a reference for software developers and practitioners interested in best practices for creating tagged and accessible PDF files. Ranging from publications to transactional records the collection represents a cross-section of document types reflecting the wide variety of uses for PDF technology. Documents included in the PDF/UA Reference Suite demonstrate correct tagging in a number of sophisticated cases, including:
- Content spanning multiple pages
- Complex table structures
- Interactive forms
- Links targeting structure elements
- Scanned documents
Matterhorn Protocol 1.1 (PDF/UA-1)
To promote the adoption of PDF/UA - the ISO standard for accessible PDF - by software developers, service bureaus and those interested in document accessibility, the PDF Association's PDF/UA Technical Working Group has developed the Matterhorn Protocol, a list of all the possible ways to fail PDF/UA-1. The 1.1 release of the Matterhorn Protocol, released in April 2021, adds a new failure condition and provides several clarifications. The PDF file is tagged to reflect current best-practice in tagging PDF documents for accessibility and reuse.
Cal Poly PDF/VT-1
The Cal Poly Graphic Communications PDF/VT-1 Test File Suite provides a collection of four sets of graphically rich, robust, valid PDF/VT-1 files for testing and demonstrating products claiming support of consumption of files conforming to the ISO 16612-2 PDF/VT standard.