<p>I believe you are asked to verify info already submitted, and to update anything since it was sent in. If you are on any medications, you will be asked to turn them in for review. If there are any current issues, you may be sent to that duty station for additional screening, which could hold up your inprocessing on I-day. Lastly, there have been rare occassions where candidates have been sent home right then and there, for either something that showed up on an exam unexpectedly, or for failing a color vision test (which gets tested on I-day).</p>