Not sure how the hanging of promotional material in specifically designed boxes would need instruction but TFL obviously think they need it.

I took this on an underground platform (London) this month. I am suprised and amused on a few levels. The need for this sticker which is about 5×8 inches in every poster box (it was visible in all units on the platform) is odd, 1) a person who fits advertising has probably been shown how to use the poster hanging box by their manager. 2) To assume that this is the first one [poster] they fit it in is an absurd idea. 3) the addition of the helpline in case of a crisis – I would love to work on that helpline!
4) this post is crap but I feel I have so much to say about such a waste of a large sticker which seems to patronize it’s target user and serve no real lasting function. Good usability points but is it nessesary?