@Doitsu
Thanks for your reply. My EPUB did not include this
com.apple.ibooks.display-options.xml file which is, as you confirm it, still required by Apple.
It's surprising after so many years this way, that iBook users do not routinely add it to their EPUBs. It's
their device and it's
their problem... (you see that I am not selling anything)...
If they override the embedded font containing the
nnbsp, they probably need to use a font that recognizes it? Maybe iBooks is still not aware of it (contrary to ADE 2.0.+)?
Here is an EPUB with the four Amasis30 fonts embedded and six nnbsp for each paragraph. I added the
nnbsp to the font but did not include the
apple file. iBooks readers should have problems reading it...