Now there is just one rate that trades within a narrow band with a reference rate set by the central bank daily in conjunction with local financial institutions.

WSJ: U.S. Forges Deeper Myanmar Ties

Besides looking at ancient scrolls, the multispectral scanner can compare things like bank notes and passports with reference documents of known provenance.

ECONOMIST: Monitor

In a modest but significant step towards liberalising its currency, China loosened the trading limits for the yuan, allowing prices against the dollar to fluctuate by up to 1% either side of the reference rate set each day by the Chinese central bank.

ECONOMIST: Business this week

In Switzerland, which like the U.K. isn't part of the euro zone, the central bank has used the euro as its external reference point in its efforts to keep the Swiss franc's value stable.

WSJ: Banks Prep for Life After Euro

The yuan hit a high against the U.S. dollar under the current system Monday, after the central bank guided the currency to its strongest level via a reference exchange rate.

WSJ: U.K. Banks Sell $245 Million Dim Sum Bonds in Singapore

Before the advent of the euro, Germany's mark was Switzerland's main point of reference including a period in the 1970s when the Swiss National Bank pegged the franc against the mark to rein in a surge in the Swiss currency.

WSJ: Banks Prep for Life After Euro

In finding Barclays guilty of attempting to manipulate the important Libor borrowing rate, the benchmark rate for bank-to-bank lending, the Financial Services Authority (FSA) made an elliptical reference to this conversation.

BBC: What did Bank of England say to Barclays about Libor?

Now, officials at the Swiss National Bank are considering what currency or basket of currencies would replace the euro as its reference point for the currency ceiling, according to a person familiar with the situation.

WSJ: Banks Prep for Life After Euro