The title used doesn't really make much difference, ereaders only looks at the type I believe.
calibre has an interface for adding
useful semantics, and won't allow you to create multiple versions of a semantic when that will result in check book complaining (at least, I hope and assume it does) that you have too many of them, in blatant violation of the spec and ereader implementations.
e.g. How do you expect the book to "Start Reading" in two different places at once?
Feel free to add custom semantics, but only you will know about them, because ereaders certainly won't.
