Coffee Break: Join us on Wednesday, April 5th at 10am PT to chat with Ben Gaines, Director of Product Management for Adobe Analytics. Ben will be online to answer your Analytics and Adobe Summit questions.
Upvoted this as it's a problem I ran across for the first time today: I tried to classify something as the value "0" (i.e. the number zero), and, when I downloaded the Classification file to check the upload, that field was blank.