Set the pdfstandard variable to produce tagged PDFs
conforming to PDF/A, PDF/X, or PDF/UA standards. For example:
pandoc -V pdfstandard=ua-2 --pdf-engine=lualatex doc.md -o doc.pdf
Multiple standards can be combined:
---
pdfstandard:
- ua-2
- a-4f
---
The required PDF version is inferred automatically. This feature requires LuaLaTeX in TeX Live 2025 with LaTeX kernel 2025-06-01 or newer.