For prices in U.S. dollars, U.K. pounds, and euros, the dollar ($), pound (£), and euro (€) symbols are sufficient to identify the currency. For other currencies, use the three-letter currency abbreviations established by the International Organization for Standards (listed by country at http://www.xe.com/iso4217.php). These codes are made up of a country's two-character Internet country code, plus a third character denoting the currency unit, which may or not be mnemonic (e.g., CAD for the Canadian dollar, but ARS for the Argentine peso). CMS16, 9.22, recommends these codes for "formal usage," and they are used in online currency-conversion utilities. At this XE site also are found links to a list of obsolete euro-zone currency abbreviations (some used in the examples below), and to world currency symbols as used by various national currencies.
A space should follow initial letter abbreviations (DEM, ITL, etc.) but not initial symbols (£, €, etc.). Always use a period as the decimal point (i.e., replace the decimal comma in European currencies with a period). If the amount is a round number, drop the ".00" if included with the amount.
Non-U.S. currencies using the dollar sign ($): Use the three-letter currency code + dollar symbol + amount (no spaces; see the Canadian dollar example below). Ditto for non-U.K. currencies using the pound sign (£). Note also that the Japanese yen and the Chinese yuan renmimbi use the same symbol (¥), so the country must be identified when naming these currencies (CNY¥ or JPY¥).
€40, €40.25, EUR 30 (euros)
£120 (British pounds), IEP£50 (Irish pounds)
NLG 340 (Netherlands guilders)
FRF340, FRF340.60 (French francs)
DEM 120, DEM 125.50 (German marks)
ITL 120,000 (Italian lire)
CAD$300 (Canadian dollars)
Names of currencies are not capitalized or italicized: dollar, pound, yen, not Dollar, Pound, Yen). This includes archaic currencies: thaler, not Thaler; gulden, not Gulden.