As others indicated the workbook is NOT iso compliant and in fact has active measures to not be.
The more I think about it - the more I think the right format for the workbook would be markdown. There are a number of good reasons for this starting with the fact it divorces the presentation from the content. In fact, this very post sort of proves my point because it is written in – markdown.
From there a means could easily be provided to covert the text into a nice looking document. In fact, it would be close to trivial to provide a web site, and cross platform executable to then print a nice rendition.