As I also said before, italic is a form of emphasis, just that it covers different types of emphasis. If something is italic, then it is visually emphasised, even if it is the title of a work. But it would be better to use <cite> for works. There is perhaps a use case for <i> for foreign words, but equally foreign words in English text are naturally emphasised. So overall I don't think anything more than <cite> and <em> are needed, and you have <strong> if you really want to shout. The <i> tag is a relic that people are in indecision over.
|