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The Matterhorn Protocol 1.1

To promote 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.

NOTE: The Matterhorn Protocol 1.1 (PDF, 692 kB) conforms to PDF/UA-1 (ISO 14289-1) and to PDF/A-2a (ISO 19005-2), and is presented as a reference-quality PDF/UA file.



Version 1.1

Published by the PDF Association


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