If I write something that is likely to be changed by the distribution system or by the actions of collaborating authors, what do I own? What if, when I write a blog article I come back and regularly change, update, and correct the original, and add comments? Do I have a way of knowing if people who read the original will know that I've made corrections or changes? These are difficuly questions, and one way to help answer them is to develop registration systems to help identify and describe works and their owners (or creators).