Allow for eBraille compliant Uber-EPUBs, i.e. do not require the default rendition to be braille

[egli]

At SBS we are toying with the idea of producing "Uber-EPUBs" that contain the text of the book, the audio and the Braille all in one EPUB. This would simplify our product portfolio, we could just distribute one all-encompassing format to our customers.

Of course we would like these "Uber-EPUBs" to be compliant with the eBraille standard. However if I understand correctly the eBraille standard mandates that the default rendition must be braille.

Could this requirement be somewhat relaxed to leave room for the idea of an "Uber-EPUBs" that is still an eBraille publication?

[mattgarrish]

To be an ebraille file the default rendition needs to be braille. That makes sense to me as it's the only rendition you can ever be assured will render.

Aren't you just proposing a multiple rendition epub rather than strictly an ebraille file, though? An ebraille rendition of the content should be a conforming epub rendition, so from an epub perspective there's nothing wrong with adding it to the container as a second or third rendition of the content.

The requirement that the ebraille rendition come first only applies if you're bundling it up with a .ebrl extension, but in this case you'd be making a .epub.