After reading some previous questions about provisionals, especially from inventors wanting to write them themselfs and consult an attorney only for the non provisional, I was wondering, how much do you have to screw up your application to actually lose the priority on at least some of the claims?
Or to be more specific, I've seen US patents claim different prioritys with continuations and continuations in part, but the patents never mention which priority they actually claim for which claim. So I figure that's for the court to decide.
(I say priority, what I mean is the date considered for prior art, so actually that would be the filing date?)
Now my understanding of provisionals is, that if you add new substantial matter for the non provisional (which seems to be no problem), the new matter gets the new filing date and the old stuff gets the old date. But where does this lead in practice? If I write a very good description of my invention, inclduing everything I can think of and the attorney then rewrites some parts to fit patent speech, (e.g. adding value ranges, defining some things as methods or embodiments where I left out those terms, etc.), could that lead to newer prior art beeing cited against me?
And if yes, to what extend? I'd appreciate the relevant patent law citation, too.
In my opinion this is a rather difficult question and I want to stress that it's always better to let an attorney do that work from the beginning on, because for example of questions like this, but we are getting many questions from inventors that cannot (yet) afford an attorney, plus I'd like to know, too.