Originally Posted by Jellby
None. An ePUB can have several <title> and <author> (well, <creator>) tags, so you can just have them all. At least for <creator> that seems the most logical.
Yes, the standard allows multiples. But is this really the wanted effect? Pretty much every RS out there would just pick the first <title> element and display that and only that.
And if the epub is a collection of, say, 50 short stories and thus has 50 different <creator> elements in the OPF... well I don't even want to imagine what the average RS would to. I'd say crash, but that's just being cynical.
There's a great difference between what the standard says and what the RSs do.