The solidus is a punctuation mark used to indicate fractions including fractional currency. It may also be called a shilling mark, an in-line fraction bar, or a fraction slash.

The solidus is similar to another punctuation mark, the slash

Slash (punctuation)

The slash is a sign used as a punctuation mark and for various other purposes. It is now often called a forward slash , and many other alternative names.-History:...

, which is found on standard keyboards; the slash is closer to being vertical than the solidus. These are two distinct symbols that traditionally have entirely different uses. However, many people no longer distinguish between them, and when there is no alternative it is acceptable to use the slash in place of the solidus.

Both the ISO

International Organization for Standardization

The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...

 and Unicode

Unicode

Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

 designate the solidus as and the slash as . This contradicts long-established English typesetting terminology.

History

The names solidus and shilling mark have the same background. In the British Commonwealth, before decimalisation

Decimalisation

Decimal currency is the term used to describe any currency that is based on one basic unit of currency and a sub-unit which is a power of 10, most commonly 100....

, currency sums in pound

Pound sterling

The pound sterling , commonly called the pound, is the official currency of the United Kingdom, its Crown Dependencies and the British Overseas Territories of South Georgia and the South Sandwich Islands, British Antarctic Territory and Tristan da Cunha. It is subdivided into 100 pence...

s, shilling

Shilling

The shilling is a unit of currency used in some current and former British Commonwealth countries. The word shilling comes from scilling, an accounting term that dates back to Anglo-Saxon times where it was deemed to be the value of a cow in Kent or a sheep elsewhere. The word is thought to derive...

s, and pence were abbreviated using the '£

Pound sign

The pound sign is the symbol for the pound sterling—the currency of the United Kingdom . The same symbol is used for similarly named currencies in some other countries and territories, such as the Irish pound, Gibraltar pound, Australian pound and the Italian lira...

' symbol, the 's.' symbol, and the 'd.' symbol (collectively £sd

£sd

£sd was the popular name for the pre-decimal currencies used in the Kingdom of England, later the United Kingdom, and ultimately in much of the British Empire...

) referring to the libra, the solidus

Solidus (coin)

The solidus was originally a gold coin issued by the Romans, and a weight measure for gold more generally, corresponding to 4.5 grams.-Roman and Byzantine coinage:...

, and the denarius

Denarius

In the Roman currency system, the denarius was a small silver coin first minted in 211 BC. It was the most common coin produced for circulation but was slowly debased until its replacement by the antoninianus...

. The 's.' was at one stage written using a long s

Long s

The long, medial or descending s is a form of the minuscule letter s formerly used where s occurred in the middle or at the beginning of a word, for example "ſinfulneſs" . The modern letterform was called the terminal, round, or short s.-History:The long s is derived from the old Roman cursive...

, ∫ that was further abbreviated to the ⁄ symbol, and suppression of the 'd.'; thus '2 pounds, 10 shillings, and 6 pence', often written as £2 ⁄ 10 ⁄ 6 (as an alternative to '£2 10s. 6d.'), and '10 shillings' would often be written as 10 ⁄ -. This usage caused the names solidus (given the abbreviation's historical root) and shilling mark to be used as names for this character.

Currency

The shilling mark is used to denote shillings, see the History section above.

Mathematics

The solidus is used in the display of ratios and fractions as in constructing a fraction using superscript and subscript as in ¹²³⁄₄₅₆, or on the same level as in 23⁄50.

The solidus is found in many legacy Apple Macintosh character sets. It can be typed on a Macintosh computer (with US keyboard layout

Keyboard layout

A keyboard layout is any specific mechanical, visual, or functional arrangement of the keys, legends, or key–meaning associations of a computer, typewriter, or other typographic keyboard....

) by pressing Option+Shift+1. Systems capable of fine typography display this result as a true fraction with small numbers.

Unicode

Unicode

Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

 also distinguishes which may be more oblique than the normal solidus character.

The solidus can be typed on Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

as Alt-8260 and the division slash as Alt-8725.