[Quoth]

Originally Posted by PeterT

See https://www.mobileread.com/forums/sh...d.php?t=119175

Try to think of the calibre library as a black box; ignore what is under the covers. Don't browse it expecting to see what items the way you want to.

Calibre will also change the filename of English filenames.

Originally Posted by jhowell

In case it was not clear the save to disk function is used to make a copy of a book file outside of your calibre library. It has nothing to do with the file names used within a library.

Even then for any decent ereader the filenames are not important. The Title, Author (and on Kobo: collection, series and subtitle) will be as desired.

Don't look inside the box at all, the Calibre Library storage.