What did the London anti-corruption summit achieve?

Today's summit was about backhanders and bribes, but the definition of corruption was widely drawn.

The preoccupation was with cleaning up the financial system rather than rotten governments.

There are many places in the world where the rich and the sometimes crooked can hide their wealth out of the reach of the authorities.

"Tackle corruption and you tackle poverty and terrorism" David Cameron proclaimed today. Campaigners couldn't agree more.

The United States was similarly on message - but the world's biggest economy failed to sign up to a key pledge: the creation of a global public register of company ownership.

Only Britain, France, Kenya, Afghanistan, the Netherlands and Nigeria put pen to paper.

People think of tax havens as being remote, exotic, islands but the United States stands accused of being one of the worst offenders. Today it did itself few favours.

As it stands, places like the Cayman Islands feel able to boast of having higher standards of transparency.

Whether it's companies, foundations, property or trusts, there's a need to know who owns what around the world.

Forty countries and jurisdictions have agreed to share company ownership information with each other.

It's a step forward which should allow the taxman and the police to rummage around offshore in a way that hasn't been possible to-date, but the public will be kept at bay. It's transparency in private.

Campaigners target David Cameron - but Britain has been behind what progress there has been on forcing others be be less secretive.

The "gold standard", as Cameron puts it, is full public disclosure. That remains a long way off.