Calibre writes several metadata entries to the .opf file in the .ePub file that are ignored by ePub readers and apps. For example:
Is there any way to prevent Calibre from writing these non-standard metadata entries to the .opf file in the .ePub file or to automatically remove them when saving the .ePub file to a different folder?
Code:
<meta content="4.0" name="calibre:rating" />
<meta content="Doe, John" name="calibre:title_sort" />