Pardon my ignorance, but where are the text strings that I would need to translate, i.e., danger, caution, notice, etc?
Actually, this is a little more complicated than I thought. I just checked the EDD and this is what it uses for most of the Prefix rules:

This is "clever" because it simply means that if you choose type="danger", you will get the prefix "DANGER". (The note.type Character Format uses Uppercase.). The problem is that you don't want to translate all of the type choice values, because anywhere a <note> is used in a localized document, you will have to change it's attribute value. *** You definitely don't want to do this. ***
The best approach is to edit the EDD so that it doesn't use <$attribute[type]>; instead, you will need a series of ElseIf elements: (pseudo-code) if [type="danger"] then prefix = (translated string danger).