It Is Friday,

and the weekend begins tonight,

so if you are in London or going to visit the city I guess at some time you will travel on the tube as Londoners call it, to others the London Underground, (no it is not a terrorist organisation) or in the US the subway, so here is your mission, if you take the ride, spot official looking unofficial signs like these,

 they can of course be quite small,

and not that easy to spot,

but can be expected anywhere,

 some keep to the same seats,

 and offer travel advice,

 for people that do not want to drink and drive home, you can see more of these signs here, a great way to make the tube journey seem shorter.