PDF/UA is the common name for ISO 14289. An international standard approved in 2012, PDF/UA defines how to represent electronic documents in the PDF format in a manner that allows the file to be accessible. The standard identifies PDF components and properties relevant to this objective and provides requirements and restrictions on the form of their use.
PDF was not originally designed for accessibility; the focus was on providing accurate and reliable on-screen and printed results for page-based content. In 2000 the PDF specification was extended by a mechanism called tagging to make it possible to add structure and semantics to page content. PDF/UA defines the correct use of PDF tagging for maximum accessibility.
In parallel with W3C's Web Content Accessibility Guidelines (WCAG 2.0) project, AIIM and Adobe Systems started the PDF/UA Committee in 2004 to explore and develop specific technical requirements for accessible PDF. Following the ISO standardization of PDF in 2008, the working document was redrafted to use ISO 32000, and PDF/UA entered the ISO standard publication track. In 2010, PDF/UA was accepted as an ISO New Work Item. In 2012, PDF/UA was published as ISO 14289.