It’s probably worth spending a few minutes looking into PDF/A, which is a subset of PDF designed for archival. While it might not be a perfect fit for your need

It’s probably worth spending a few minutes looking into PDF/A, which is a subset of PDF designed for archival. While it might not be a perfect fit for your needs (though it almost certainly is), being ISO standardised it might be a good source of documentation. https://en.m.wikipedia.org/wiki/PDF/A https://en.m.wikipedia.org/wiki/PDF/A