2.2.3 [W3C-EPUB3] Section 3.4.12. The spine Element

C0006: There are no mechanisms to override the default direction

The specification states:

 › 3.4.12 The spine Element
  
 The spine element defines the default reading order of the given Rendition of the EPUB 
 Publication content by defining an ordered list of manifest item references.   
 ...
 ... Reading Systems may also provide mechanisms to override the default direction (e.g., 
 buttons or settings that allow the application of alternate style sheets).

EdgeHTML Mode

There are no mechanisms to override the default direction.