I was reading https://www.unicode.org/versions/Unicode10.0.0/UnicodeStandard-10.0.pdf on a Sony Digital Paper device and tried to scribble some notes and make highlights but I couldn't. I still couldn't after ensuring that the pen was charged and could write on other PDFs.
Since Evince told me just "Security: No", since the Digital Paper's UI for designating non-editability is easy to miss and since there's no password required to open the file, it took me non-trivial time to figure out what was going on. Upon examining the PDF in Acrobat Reader, it turned out that even though the PDF can be viewed, printed and copied from without artificial restrictions, there are various restriction bits set for modifying the file. (Screenshot: https://hsivonen.fi/screen/unicode-pdf-restrictions.png ) It doesn't make sense to me that the Consortium restricts me from adding highlights or handwriting if I open the Standard on an e-Ink device even though I can do those things if I print the PDF. I'd like to request that going forward the Consortium refrain from using restriction bits or any "security" on the PDFs it publishes. -- Henri Sivonen hsivo...@hsivonen.fi https://hsivonen.fi/