[darryl]

I think davidfor did change the content server to cownload kepub files as kepub.epub to Kobo devices.

In the meantime, I have had a look at the relevant source and applied my very limited Python knowledge with surprising success. Two minor changes to add the kepub format in content.py fix the problem. This means, of course, that the content server now supports not only epub, mobi and azw3 but also kepub. Sounds much more impressive than it is! I will have a look at submitting a patch according to the instructions in the manual. However, one consequent change will be necessary to metadata plugboards. Trying to add a plugboard for the content server specifying kepub as the format in the preferences gui still results in an error message that kepub is not supported by the content server. If I get a chance I will see if I can fix this before trying to submit any changes.

EDIT: Please see my further post below.