Two years after the publication of the standard PDF/UA-1:2012 (ISO 14289-1) a slightly modified version PDF/UA-1:2014 was published.
This ISO standard is the first document which is published in an accessible version by the ISO. The ISO was supported by two members of the PDF Association and their.
The new version features small adjustments and clarifications. PDF/UA-1:2014 replaces the 2012 version.
Additional details can be found on pdfa.org.