How to fold your Metro

I seldom catch the Tube at peak times - being an Australian I don't cope well with personal space slightly smaller than the width of my shoulders - but I did this morning, and marvelled anew at the British ability to develop new social rules for changing circumstances.

Metro is a free newspaper picked up at Tube stations and usually left by users on the train. (Its articles are, to be polite, brief, and largely based on wire copy, but do give you the basics of the day's news.) It started no more than two, or perhaps three, years ago, and there are now, I realised with an anthropological eye on the Northern Line this morning, all sorts of "rules" about its use.

When leave it you should carefully fold it in half - preferably still in pristine condition - as though your butler had just ironed it, as tradition says aristocrats used to get their Times. It can either be left on the seat, or the ledge behind them, although the seat seems preferable. It is then allowable for someone who wants to read it to select this seat, although normally you can get nasty looks if you leap down the carriage for a particular position.

But the protocol suggests you should wait until the person who left it has got off the train before leaning over from another seat to pick it up, it seems.

I'm always amazed when people suggest that Londoners are rude and abrupt - having moved here from Bangkok, I've always found them to be astonishingly polite and mannered.

And if you want people to smile at you, get a dog. On the way home from Battersea this afternoon (laden with Battersea logo bags and with Prince) I struck up two conversations with total strangers, and exchanged smiles with several more.