How to generate PDF 2.0 output using pdflatex

Question

Based on the manual of PDFLaTeX, it seems pdflatex can support generating pdf up to version 1.7 (ISO 32000-1:2008) using \pdfminorversion=7. To use PDF 2.0 (ISO 32000-2:2017), can I define a major version number =2 alongside with \pdfminorversion=0 or something like that?

Answer 1

You can generate a PDF document that claims to conform to the PDF 2.0 specification using luatex (tested with version 1.10.0) as follows:

\documentclass{article} 
\begin{document}
\directlua {   
  pdf.setmajorversion(2)   
  pdf.setminorversion(0) 
} 
Foo. 
\end{document}

On this simple example, the output does seem compatible with the standard, at least according to the pdf-tools online validator. That won't necessarily be the case for more complex documents, even if the 2.0 specification has been designed as much as possible as a superset of previous versions, to allow graceful degradation for software that has been developed for older versions of the standard.

Answer 2

At present the answer is no for pdfTeX, but plans for TeX Live 2020 work are already in place and I (and others) will look to add a new primitive to support this (likely \pdfmajorversion). The main issue is not the primitive itself but the supporting 'environment': there are lots of places that test for the minor version as a boundary/cut off for different features, and picking up that 2.0 > 1.4 is going to be fun!