Pound sign

The pound sign (£) is the symbol for the pound unit of sterling – the currency of the United Kingdom and its associated Crown Dependencies and British Overseas Territories and previously of Great Britain and of the Kingdom of England. The same symbol is used for other currencies called pound, such as the Egyptian and Syrian pounds. The sign may be drawn with one or two bars depending on personal preference, but the Bank of England has used the one-bar style exclusively on banknotes since 1975.
In the United States, "pound sign" refers to the symbol # (number sign). In Canada, "pound sign" can mean £ or #.
The symbol derives from the upper case Latin letter L, representing libra pondo, the basic unit of weight in the Roman Empire, which in turn is derived from the Latin word libra, meaning scales or a balance. The pound became an English unit of weight and in England became defined as the tower pound (equivalent to 350 grams) of sterling silver. According to the Royal Mint Museum:
However, the simple letter L, in lower- or uppercase, was used to represent the pound in printed books and newspapers until well into the 19th century. In the blackletter type used until the seventeenth century, the letter L is rendered as L {\displaystyle {\mathfrak {L}}} .
When used for sterling, the pound sign is placed before the numerals (e.g., £12,000) and separated from the following digits by no space or only a thin space. In the UK, the sign is used without any prefix. In Egypt and Lebanon, a disambiguating letter is added (E£ or £E and £L respectively). In international banking and foreign exchange operations, the symbol is rarely used: the ISO 4217 currency code (e.g., GBP, EGP, etc.) is preferred.
In Canadian English, the symbol £ is called the pound sign. The symbol # has several uses and is sometimes called the pound sign too, though it is most often known as the number sign. (Telephone instructions for equipment manufactured in the United States often call # the pound key.)
In American English, the term "pound sign" usually refers to the symbol # (number sign), and the corresponding telephone key is called the "pound key". (As in Canada, the # symbol has many other uses.)
Banknotes issued by the Bank of England since 1975 have used only the single bar style as a pound sign. The bank used both the two-bar style (₤) and the one-bar style (£) (and sometimes a figure without any symbol whatever) more or less equally from 1725 to 1971 intermittently and sometimes concurrently. In typography, the symbols are allographs – style choices – when used to represent the pound; consequently fonts use U+00A3 £ POUND SIGN (Unicode) code point irrespective of which style chosen, (not U+20A4 ₤ LIRA SIGN despite its similarity). It is a font design choice on how to draw the symbol at U+00A3. Although most computer fonts do so with one bar, the two-bar style is not rare, as may be seen in the illustration above.
In the eighteenth-century Caslon metal fonts, the pound sign was identical to an italic uppercase J, rotated 180 degrees.
In the Unicode standard, the pound sign is encoded at U+00A3 £ POUND SIGN (&pound;) Whether the glyph is drawn with one or two bars is a type designer's choice as explained above; the key point is that the code is constant irrespective of the presentation chosen.
The encoding of the £ symbol in position xA3 (16310) was first standardised by ISO Latin-1 (an "extended ASCII") in 1985. Position xA3 was used by the Digital Equipment Corporation VT220 terminal, Mac OS Roman, Amstrad CPC, Amiga, and Acorn Archimedes.
Many early computers (limited to a 7-bit, 128-position character set) used a variant of ASCII with one of the less-frequently used characters replaced by the £. The UK national variant of ISO 646 was standardised as BS 4730 in 1985. This code was identical to ASCII except for two characters: x23 encoded £ instead of #, while x7E encoded ‾ (overline) instead of ~ (tilde). MS-DOS on the IBM PC originally used a proprietary 8-bit character set Code page 437 in which the £ symbol was encoded as x9C; adoption of the ISO/IEC 8859-1 ("ISO Latin-1") standard code xA3 only came later with Microsoft Windows. The Atari ST also used position x9C. The HP LaserJet used position xBA (ISO/IEC 8859-1: º) for the £ symbol, while most other printers used x9C. The BBC Ceefax system which dated from 1976 encoded the £ as x23. The Sinclair ZX80 and ZX81 characters sets used x0C (ASCII: form feed). The ZX Spectrum and the BBC Micro used x60 (ASCII: `, grave). The Commodore 64 used x5C (ASCII: \) while the Oric computers used x5F (ASCII: _). IBM's EBCDIC code page 037 uses xB1 for the £ while its code page 285 uses x5B. ICL's 1900-series mainframes used a six-bit (64-position character set) encoding for characters, loosely based on BS 4730, with the £ symbol represented as octal 23 (hex 13, dec 19).
The logo of the UK Independence Party, a British political party, is based on the pound sign, symbolising the party's opposition to adoption of the euro and to the European Union generally.
A symbol that appears to be a double-barred pound sign is used as the logo of the record label Parlophone. In fact this is a stylised version of a Fraktur L ( L {\displaystyle {\mathfrak {L}}} ), standing for Lindström (the firm's founder Carl Lindström).
The pound sign was used as an uppercase letter (the lowercase being ⟨ſ⟩, long s) to signify the sound [ʒ] in the early 1993–1995 version of the Turkmen Latin alphabet.