You could put a remark in the .cr2 file. Just preface it with a # and a space. You can create a Vicki based character, but if it uses someone else's morphs, you can only distribute MOR files - files that set the morph dial settings but do not include the morphs themselves. If you create your own morphs, you can distribute them in a stripped down .cr2 file. (The DAZ3D.com site has more information.) You don't need to ask DAZ permission for this. If you are going to create a character based on someone else's morphs besides DAZ, I'd contact them to be on the safe side.