[bookman156]

Mostly an author's intention for using italic is no more than convention, and because it usefully prevents say book titles being read as part of the text. From an editorial perspective, 'house style' dictates use of italic, and this is mostly based on books such as The Chicago Manual of Style. It makes sense in many of its proclamations, but to suppose the author has any degree of intention beyond house style is reading more into it than is there, and also providing a level of invisible annotation that is dependent on the annotator being almost godlike in their dedication to tagging at a granularity that the reader simply supplies naturally (do I need a Latin phrase tagged as Latin, I can see it's Latin). As for translation of phrases, ebook software can do that if the author has been so 1950s as not to do it in the text.

To me this obsession with micro-data seems to be solely for the collation of automatic lists, which are only as good as the annotator. And who is the annotator? The author or someone in an ebook production house? Frankly, speaking as a print editor, much italic in print books is not necessarily supplied by the author in the first place, but rather by the editor ensuring that the typescript conforms to house style. Mostly the only italic of importance supplied by the author is in fiction and is limited to the odd word of emphasis. The rest is house style. If book titles are italicised at such-and-such a publisher, they will be, regardless of how the author presented them. If the preference is for titles in inverted commas and not italic, that's how they will be done, even if the author italicised them.