[DiapDealer]

That is done by design. It's valid code. If you don't want the span code, then don't use the style buttons (or their assigned keyboard shortcuts) in Book View. Book View edits (even simple ones using the same button) are entirely different beasts than Code View edits. That's what people often fail to understand. We can better control what code gets generated by the styling buttons in Code View, but we have very limited options as to what code Qt generates in Book View with the same buttons (and same shortcuts). We've chosen the option that absolutely guarantees spec-compliance.

And the bottom line is: those who make wysiwyg edits don't really get to complain about the code that's generated for them. You can't have it both ways. If you're particular about the code contained in your ebook, then make all of your edits in Code View. It's really that simple.