The three aspects of User Stories in the practice of XP
Just enough information to remind you about the conversation - it's just a representation of the story at a point in time
User Story Cards as Vacation Photos
Explore - how will we know when it's done?
Explore examples to illustrate when the need is met.
Confirmations focus the conversation, deal with them one at a time. More cards may sprout out for later, or be discarded as unnecessary.