I've noticed that these are written to the content OPF file thus:
Code:
...
<dc:identifier opf:scheme="LOWYPUB">islamic-state-propaganda-and-mainstream-media</dc:identifier>
...
Wondering whether they should be, given the only place LOWYPUB etc are defined is on this computer.
They haven't caused me any problems, but I only read EPUBs on Windows with calibre and sigil, and on Android with Moon+ (via ES File Explorer). I don't make any use of the metadata outside of calibre. FWIW: I strip the non-DC elements, and covers, out of the EPUBs with Modify.
BR