To promote adoption of PDF/UA by software developers and document testers alike, the PDF Association's PDF/UA Competence Center developed the Matterhorn Protocol, a list of all the possible ways to fail PDF/UA.
Following the requirements of PDF/UA, the document consists of 31 Checkpoints comprised of 136 Failure Conditions.
The 1.02 release of the Matterhorn Protocol, dated April 30, 2014, provides minor editorial corrections. One checkpoint - 08-003 - is now designated 01-007.
NOTE: The Matterhorn Protocol 1.02 (PDF, 339kB, 2014-06-26) is delivered as a PDF file conforming to PDF/UA-1 (ISO 14289-1) and to PDF/A-2a (ISO 19005-2). It is a reference-quality PDF/UA file.