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PDF/A and external references

November 2025 by Peter Wyatt

PDF/A ensures reliable long-term rendering by embedding fonts, images, and color profiles, but URLs can still appear in text, hyperlinks, bookmarks, annotations, metadata, and embedded files.

Link annotations and URI Actions define clickable destinations, but PDF/A restricts certain action types to prevent external dependencies.

Guided by clear policies, comprehensive audits of both visible and hidden references help maintain authenticity, accessibility, and long-term integrity of PDF/A documents and digital collections.

PDF/A ensures reliable long-term rendering by embedding fonts, images, and color profiles, but URLs can still appear in text, hyperlinks, bookmarks, annotations, metadata, and embedded files.

Link annotations and URI Actions define clickable destinations, but PDF/A restricts certain action types to prevent external dependencies.

Guided by clear policies, comprehensive audits of both visible and hidden references help maintain authenticity, accessibility, and long-term integrity of PDF/A documents and digital collections.

Perfecting PDF Lexical Analysis

April 2021 by Peter Wyatt
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This PDF file tests parsing valid combinations of adjacent PDF tokens both in the body of a PDF as well as in PDF content streams.

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March 2021 by Thomas Zellmann
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Thomas Zellmann, evangelist from the PDF Association, explains why PDF is not only “digital paper” but also one of the … Read more

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February 2021 by Dietrich von Seggern (callas software GmbH)
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The ISO-standardized PDF format and subset formats facilitate digital document solutions for today and tomorrow.

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February 2021 by PDF Association staff
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EA-PDF establishes high-level requirements for using PDF technology to package email for long-term preservation.

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February 2021 by Michael Karbe (Actino Software GmbH)
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As the AstraZeneca vaccine contract debacle makes clear, redacting PDF involves more than just the page; other objects have to … Read more

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January 2021 by Duff Johnson
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PDF/A-4 is essential to losslessly archiving PDF files that use current-generation PDF 2.0 technology… even including scanned documents. From modern … Read more

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January 2021 by Carsten Luedtge (Compart GmbH)
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How do companies stay agile enough in their document and output management to meet increasing customer expectations for speed and … Read more

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December 2020 by PDF Association staff
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27 years after Adobe shipped the first PDF viewer the portable document format has replaced paper as the final format … Read more

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November 2020 by Peter Wyatt
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The original PDF Issue Tracker corpus generated a lot of interest from the PDF technical community; now version 2 of … Read more

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October 2020 by Duff Johnson
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Introduction Akin to our earlier series on the Mueller Report PDF, this article provides cultural framing and technical background for … Read more

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September 2020 by Bernd Wild (intarsys GmbH)
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The history of integration of digital signatures in PDF together with the underlying public standards like PAdES, CAdES and XAdES … Read more

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