I have the same question but need to implement it. The v5 release documentation states that: "Introduced an option to enable or disable the DITA-OT preprocessing for Native PDF output. Enable this option if your content requires DITA-OT-based normalization or custom DITA-OT plugins during processing...

That worked perfectly. Thank you.

Using JavaScript I would like to find out what the 'lang' attribute variable is set to. I have used:document.getAttribute('lang').value;document.head.parentNode.getAttribute('lang').value;document.body.parentNode.getAttribute('lang').value;document.querySelector('html').getAttribute('lang').value;wi...