I thought about putting this in one of the firmware threads, but figured I'd make it its own thing since it can apply to multiple versions. And I figured that if it's okay to post the links to the dictionaries, it'd be okay to do this too since the Arphic licensed fonts are encrypted anyway and are useless outside of a Kobo e-reader and the STIX fonts are open source.
As many have noticed by now, starting in firmware 4.3X, if you switch your language to Japanese or Chinese and sync, some extra fonts are downloaded to /mnt/onboard/fonts/kobo. There may be some people out there who (for whatever reason) can't sync and wish to sideload them instead. For those people, here are the URLs (I got them from snooping around in the firmware):
These get downloaded to
/mnt/onboard/fonts/kobo/encrypted on sync:
These get downloaded to
/mnt/onboard/fonts/kobo:
I believe the licensed Arphic fonts have to be in the fonts/kobo/encrypted folder for the firmware to see/use them. As for the STIX fonts, they seem to be binary equivalent to the
v2.13 b171 release available on Github (the latest version as of this writing). Being open source, they are not encrypted either so you can place them in the root fonts folder if you like and they'll work just fine. I don't know if special things can happen/be unlocked if they're in the fonts/kobo directory, though.
That's all I've been able to find. Feel free to chime in if there's stuff I've missed.