http://www.jrothman.com/weblog/2006/10/when-requirements-spawn-requirements.html
>>A colleague asked me what to do when you're in an iteration and you realize that the story you're working on spawns other requirements. I suggested that the person add them to the product backlog (the backlog of everything you want to do for the product) and re-rank the requirements in preparation for the next iteration. "We can't do that. Our users won't let us." Why not? "Because if they find it in this iteration, they want to add it to the next iteration, if not this iteration."<<
