title_body: What are epub JSON links?
upvoted_answer: The reader should just ignore it.
  
  According to epub standard which says content should be valid XHTML or HTML5 and then  following the links through to the RFC 3987 for an URI section 2.2 a href begins with a scheme (e.g. http) and then a :
  
  I would guess that there is a reader that preprocesses a file and this converts the JSON to a link.