I read it more as "don't implement JS, 3D object rendering, slideshow transitions, sound annotations and the other 999 insane features that I'm not even aware exist"
Would require defining what features are needed. "Require PDF/A" is probably a reasonable approximation, though it would break most PDFs
Would require defining what features are needed. "Require PDF/A" is probably a reasonable approximation, though it would break most PDFs