For the past few Mondays I have been meeting people at LHR T5. I always wait by the lifts up to the lounge and this happens to also be where the crew exit via the side door from customs.
I have been amazed with the amount of crew who exit this door and then think they are off duty. Parts of uniform being removed and the worst offenders are MF ladies who remove the hats. You have been given a hat for a reason and therefore wear it until you have left the airport.
This is not a dig at mf as I have seen both fleets remove parts of uniform but show some pride in your uniform and wear the hat.