title_body: How to add a calibre bookmark txt to manifest I converted my docx into a epub file using Calibre but Smashwords is saying that the META-INF/calibre_bookmarks.txt file is not listed in the manifest.
  
  Below is their full explanation. Does anyone know how to easily add this? 
  
  File 'META-INF/calibre_bookmarks.txt' in EPUB not listed in manifest!
  Your .epub file is missing one or more elements in its manifest. A complete manifest is required for distribution to Apple. Here's how Wikipedia (http://en.wikipedia.org/wiki/EPUB) defines "Manifest":"The manifest element lists all the files contained in the package. Each file is represented by an item element, and has the attributes id, href, media-type. All XHTML (content documents), stylesheets, images or other media, embedded fonts, and the NCX file should be listed here."
upvoted_answer: Just hit this myself trying to put a book on Smashwaords. It seems that browsing a book with Calibre adds an extra file called 'calibre_bookmarks.txt'. (Smashwords spots it, but the IDPF's Epub Validator doesn't!)
  
  The solution's simple enough:
  
  
  Change the book's extension from .epub to .zip. (Eg: mybook.epub ->
  mybook.zip) 
  Open the .zip file. 
  Delete the 'calibre_bookmarks.txt' file. 
  Save and close the .zip.
  Rename it back to .epub.
  
  
  Alternative method: Don't open your books in Calibre ;-)