avox wrote: > PLinnell wrote: > > I think in theory it could be done via 'optional content' in PDF 1.5. > > AFAIK "optional content" is something else (layers).
One can just add separate objects unconnected with the pdf content or marked content annotating the graphics object in a PDF content stream. Says in the PDF ref. 5th edition page 18. Little more from there: PDF provides means for applications to store their own private information in a pdf file. This information can be recovered when the file is imported by the same application, but it is ignored by other applications. Therefore, PDF can serve as an application's native file format while it's documents can be viewed and printed by other applications.
