Actually, I don't know. I went through two years ago. If that's the case, this is for the people I have confused: The cards were part of the HR stuff everyone (not just pilots) had to go through at the beginning of indoc. You watched a video with different interpersonal scenarios, and you held up color-coded cards representing how appropriate or inappropriate you thought the behavior in the scenario was. I thought my classmate's hanging the red card on his door was funny because "inappropriate behavior" was written on the bottom of it. Sorry for the confusion.