Web links in Ovation Pro ?

A related question: is it the use of PDFMark or some other technique that produces the hot text links in ROOL’s PDF documents (e.g. User Guide, BBC BASIC Reference Manual, etc. and even within and between the aging PRMs)?

@Bernard Possibly, possibly not! ¹
The pdfmark operator is a PostScript extension that is implemented in Acrobat Distiller and Ghostscript (and possibly others), but not in PostScript printers. It allows for additional features that appear in PDFs to be defined in the PostScript file, which is destined to be “converted” to a PDF – such as links to URLs, links to other pages, links to other documents, etc. But it also covers many other uses, such as document info, bookmarks, annotations, etc.

It is certainly what I have used to set the document info, create URL links and create PDF bookmarks in my PDFs that have been done in Ovation Pro (on RISC OS).

¹ The reason I said possibly not, is that I believe the Acorn/ROOL documentation was/is authored in Adobe Framemaker, which I would imagine (total guess) creates PDFs directly, without distilling PostScript, so it would create the required links directly in the PDF document (or whatever output type is chosen).