World currencies

This catalogue counts 155 currencies with legal-tender status across its 240 countries and territories, and 17 of them are official in more than one. The ISO 4217 list carries more codes than that, because it also codes units that are nobody's cash: gold, silver, palladium and platinum, each defined as one troy ounce, the special drawing right, and XTS, reserved for testing.

For a national currency the first two letters are the country's ISO 3166 code and the third is, where possible, the first letter of the currency's name, so JP and Y make JPY for the Japanese yen. The euro breaks the pattern: EU is a code reserved for the union, not a country. Every currency also has a three-digit number. Where possible it matches the country's own numeric code, and it serves systems that do not read Latin script.

Far more than the dollars. The plain $ is the narrow sign of the US, Australian, Canadian, Hong Kong and East Caribbean dollars and a string of others, and of several pesos, the Mexican, Chilean, Colombian and Argentine among them. Where the context leaves it open, writers add letters, as in Mex$ or Ch$, or use the ISO code.

The language decides, not the currency. English puts the sign first, as in $20.50, and so does most of Latin America. Many European languages, and French in Canada, put it after the number. One euro amount reads €1,234.50 in English and 1 234,50 € in Slovak, and every currency page here prints both forms side by side.

56 of the currencies here have no sign of their own in the locale data that phones and browsers format money with, so an amount is written with the three-letter ISO code instead. The page for each of them says so and shows the code as it appears in an amount.