The PDF Association is pleased to announce the publication of Matterhorn Protocol 1.0 to promote conformance with PDF/UA (ISO 14289), the international standard for accessible PDF files, readers and assistive technology.
PDF/UA specifies how content in PDF is made accessible to users with disabilities. From reading order to fonts, PDF/UA specifies precise conditions that must be present in order for page content, form-fields, annotations, metadata and other elements of PDF files to be expressly and reliably accessible to users who depend on specialized tools and features to read and interact with electronic content.
The Matterhorn Protocol is designed to foster adoption of PDF/UA by providing a set of 31 Checkpoints and 136 Failure Conditions that help software developers exchange detailed information on PDF/UA conformance and create software to make it easier for document authors to create fully accessible PDF files and forms.
An example of a Failure Condition requiring human evaluation is 14-001: ‘Headings are not tagged.’ A Failure Condition that may be evaluated by a machine is 13-004: ‘Alternative or replacement text missing for Figure tag.’
PAC 2, the new PDF Accessibility Checker from Access for All, a Swiss non-profit foundation, is the first implementation of the Matterhorn Protocol. The company that developed PAC 2, xyMedia, is a member of the PDF/UA Competence Center, and collaborated closely on development of the Matterhorn Protocol.