18.1 ConTeXt

ConTeXt always produces tagged PDFs, but the quality depends on the input. The default ConTeXt markup generated by pandoc is optimized for readability and reuse, not tagging. Enable the tagging format extension to force markup that is optimized for tagging. This can be combined with the pdfa variable to generate standard-compliant PDFs. E.g.:

pandoc --to=context+tagging -V pdfa=3a

A recent context version should be used, as older versions contained a bug that lead to invalid PDF metadata.