Oh! Indeed, I have it. I hadn't search in the right place. I'm sorry.
It has these lines:
djv:@DJVU_file:1:koreader.app,eink-reader.app:ICON_DJVU
djvu:@DJVU_file:1:koreader.app,eink-reader.app:ICON_DJVU
doc:@DOC_file:1:koreader.app,eink-reader.app:ICON_DOC
docx:@DOC_file:1:koreader.app,eink-reader.app:ICON_DOCX
epub:@EPUB_file:1:koreader.app,eink-reader_with_blink.app,eink-reader_with_epub2.app:ICON_EPUB
htm:@HTML_file:1:koreader.app,eink-reader.app,browser.app:ICON_HTM
html:@HTML_file:1:koreader.app,eink-reader.app,browser.app:ICON_HTMLpdf
These were my options.
In fact, now I see that this functions well; I can open these file types in KOReader through Pocketbook library. Maybe the problem was due to some plugins I had installed and now uninstalled. I had other problems too...