i saw this sign on the boat from saint malo.
bras ! i think the idea is that you abandon your bra if you are leaving the UK so you can be a true european (they also had some stick on arm pit hair)

Now, i'm not stupid. i can read a bit of french. and i know that enfants means babies. and everyone knows that kids don't wear bras.
so i recon you can also leave your kids in this locker if you want.