If you see this little green tag when you get gate checked, look alive. Chances are, you'll run into this on short flights serving express routes. This tag essentially helps airlines cut down on overhead bin space.
By assigning passengers this particular tag, it means the airline wants you to pick up the bag at the gate immediately when you land. This happened to me on a recent Portland flight when all the gate agents forced all the passengers to gate-check their rollaboard suitcases on a tiny Canadair Regional Jet. The plane probably fit less than 30 people onboard so, as you can probably guess, carry-on space was not exactly in adequate supply.
In some cases, pick up can occur plane-side as you soon as you disembark. But if there's any doubt whatsoever, pick up the bag at the arrival gate when you get in. Not the baggage claim. Some airlines use different colors for this specifc tag, so just keep an eye out: United uses green while Delta uses pink.
Then again, I was the first person off the plane and there was a flight attendant training session in effect, so there was quite a bit of confusion involved. In any case, you can always go to the baggage services counter to notify them that your bag is still sitting up in arrivals if you've made the mistake and they'll bring it down to you.
