This book has text with diacritical marks with the letters.
I can’t send you an example because this editor strips it all out.
There are letters with a dot under them, over them, or a grave over them or a line over the letter. Crude examples: å é etc. But these letters are oftentime (mostly) rendered larger than the other letters so it looks really bad.
iBooks gets the typography right. ADE and Calibre get it wrong. Bookreader gets it more wrong because the size of the accented letters is excessive.