The currency sign (¤) is a character used to denote a currency when the symbol for a particular currency is unavailable. It is particularly common in place of symbols such as that of the Colón (₡), which are absent from most character sets and fonts. It can be described as a circle the size of a lowercase character with four short radiating arms at 45° (NE), 135° (NW), 225°, (SW) and 315° (SE), and slightly raised over the baseline.
It is represented in Unicode as CURRENCY SIGN (U+00A4). In HTML, the character entity reference ¤ or numeric character reference ¤ may be used.
The currency sign used to be a part of the Mac OS Roman character set, but Apple changed the symbol at that code point to the euro sign (€) in Mac OS 8.5. In non-Unicode Windows character sets, the euro sign was introduced as a new code-point. In the Unicode character-sets of Mac OS, Windows, and Unix, the two symbols each have unique code points.
The symbol is available on some keyboard layouts, for example French, Danish, Norwegian and Swedish/Finnish keyboards, because it is used in business applications.
The symbol was invented in 1972 as a replacement for the dollar sign in national variants (ISO 646) of ASCII, and, originally, also the International Reference Variant. It was proposed by Italy to allow an alternative to encoding the dollar sign. When ISO 8859 was standardized, it was placed at 0xA4 in the Latin, Arabic, and Hebrew character sets. There was not room for it in the Cyrillic set, and it was not included in all later added Latin sets. Latin 9 in particular replaces it with the euro sign.