Slash (punctuation)

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A slash or stroke, /, is a punctuation mark. It is also called a solidus, oblique, diagonal, separatrix, shilling mark, virgule, scratch comma, slant, or forward slash.

Usage

History

This symbol goes back to the days of ancient Rome. In the early modern period, in the Fraktur script, which was widespread through Europe in the Middle Ages, one slash (/) represented a comma, while two slashes (//) represented a dash. The two slashes eventually evolved into a sign similar to the equals sign (=), then being further simplified to a single dash (–).

English language

The most common use is to replace the hyphen to make clear a strong joint between words or phrases, such as "the Ernest Hemingway/William Faulkner generation". Yet very often it is used to represent the concept or, especially in instruction books.

The symbol also appears in the phrase and/or, a prose representation of the logical concept of disjunction.

The virgule is also used to indicate a line break when quoting multiple lines from a poem, play, or headline. In this case (and only in this case), a space is placed before and after the virgule. For example: "Love alters not with his brief hours and weeks, / But bears it out even to the edge of doom".

British English particularly makes use of this alternation with a hyphen in forming abbreviations. Many examples are found in writings during the Second World War. For example, 'S/E' means 'single-engined', as a quick way of writing a type of aircraft. And in the US, "O/O" is used by trucking firms or taxicabs to mean "owner-operator" (or "owned and operated by"). Notice that the phrase has a hyphen, whereas the abbreviation uses the slash.

The slash is often used, perhaps incorrectly, to separate the letters in a two-letter initialism such as R/C (short for radio control) or w/o (without). Purists strongly discourage this newer use of the symbol. However, since other uses of the slash with individual characters are highly context-specific, confusion is not likely to arise. Other examples include b/w (between or, sometimes, black and white), w/e (whatever, also weekend or week ending), and r/w (read-write).

The solidus and virgule are distinct typographic symbols with decidedly different uses. The solidus is significantly more horizontal than the virgule. The character found on standard keyboards is the virgule and while most people lump the two characters together (and when there is no alternative it is acceptable to use the virgule in place of the solidus), they are different. The solidus is used in the display of ratios and fractions as in constructing a fraction using superscript and subscript as in “¹²³⁄₄₅₆”; the virgule is used for essentially any other textual purpose.

Arithmetic

A slash is used to separate the numerator and denominator in a vulgar fraction, or as a division operator in general.

3/8    (three eighths)

x = a / b    (x equals a divided by b)

The special character Fraction slash U+2044, character ⁄ (the solidus or shilling mark proper), can be used instead of a virgule, and is preferred whenever possible. It is also found in many legacy Apple Macintosh character sets. Systems capable of fine typography should display the result as a true fraction with smaller numbers. Unicode also distinguishes the Division Slash U+2215 (∕) which may be more oblique than the normal solidus character.

Bowling

A slash is typically used to denote a spare, knocking down all ten pins in two throws, when scoring ten-pin bowling.

British money before decimalisation

Before decimalisation (15 Feb. 1971) in the UK, currency amounts in pounds, shillings, and pence were abbreviated with the characters '£', 's.' or '/', and 'd.' (such as £3, 4s., 2d., for example). The pound sign '£' refers to the Latin libra, while the 's.' and 'd.' refer to the Roman currency units sestertius and denarius respectively.

When used to express sums of shillings and pence, or shillings and no pence, '/' was often used. This is a direct throwback to the days of the long s ('ſ' or '∫'), so it is the same as the 's' of today, but wasn't followed by a full stop or space. Hence 10/6 instead of 10s. 6d., requiring no 'd.' for pence and so was quicker to write. It was also used as 10/= for 10.s, as seen below when the sum was a whole number of shillings:

 

Note however, that when the pound sterling was used in addition to shillings and pence that the solidus could not be used as a divider between the two to express the former and latter units, and the more formal style had to be resorted to for the three units, e.g. ₤1·19·11 , i.e. One pound, nineteen shillings, and eleven pence.

N.B. The raised-dot · or ' interpunct ' separating the units: a full stop on the line could be confused with a decimal point, a raised-dot or sometimes even a single dash was more often used ' ₤1-19-11 ', but the latter was better avoided, (see below).

The double-dash ' = ' , in the above table, is used to represent 'nought' (zero). In more recent times before Decimalisation Day — Mon., 15th Feb. 1971 — the double-dash for 'nought' sometimes gave way to a single dash, thus: 10/-, (although this was frowned on in the 1950s and 60s as it gave room for ambiguity with ₤1-19-11 when replacing the raised dot with a single dash. A single dash was also used to express nought when doing columns of sums, which could be potential cause for even further confusion). The double cross bar in the pound sterling symbol ' ₤ ' also gave way to the more modern single bar ' £ ' as used by even the Bank of England to-day, (though this was to be seen in the days prior to decimalisation as well).

Before the farthing became defunct in the early 60s, it was worth ¼d. Thus, an amount such as 2¼d. was read ' tuppence-farthing' and 3½d. as thrupp'nce-hap'ney (threepence halfpenny). For ease and simplification of speech ¾d. was expressed as 3 farthing(s), thus: ₤5·19·11¾ would have been read as 'Five pound(s), nineteen (shillings), eleven-three', (farthing being understood). 2/11¾ would have been similarly read 'two (shillings) eleven-three'. 1½d. would likewise be read 'three hap-ney' for ease of speech (i.e. three halfpennies). (The use of the word 'and' when expressing the final unit of more than one unit was generally left out as it could be understood in context, thus: 1/11¾ was read as 'One eleven-three' (farthing), and this was understood in the same way an American would automatically know, for instance, that 'two twenty-five' in context meant '$2.25' and not '$225.00' etc.)

It is this usage (in particular, separating shillings from pence) that brought about the name 'solidus' in the English language to refer to this character, the character ' / ' again being derived from the long s ' ∫ ' for solidus when referring to shilling(s). The use of diagonals to express fractions at the same time as the similarly shaped solidi were being used to express shilling meant a need for a means to distinguish between the two and avoid any possible confusion.

So as not to confuse ' / ' i.e. solidus for shilling, when fractions were not available on a type-writer or at a printers, insertion of a hyphen after the whole penny or pence expressed and then the fraction of the penny was sometimes used for clarity. E.g. 2/11½d. could be written out of necessity as 2/11-1/2 as two-shillings eleven-pence hap-ney. However this was often better expressed as 2s. 11-1/2d. or in larger sums, for instance, as ₤5·19·11-3/4 for ₤5·19·11¾. Here again, the dash was better not used between units to avoid confusion: ₤5·19·11-3/4 rather than ₤5-19-11-3/4. However, when super- and sub-scripts were available, they offered another alternative to avoid ambiguity and confusion, e.g. ₤5·19·11³/₄ (read: five (pounds), nineteen (shillings), eleven, three farthing), 3¹/₄d. (read: thrup'nce farthing), similarly 2¹/₂d. tuppence hap'ney, etc.)

Computing

Files

On Unix-like systems, the slash carries two distinct meanings. Its primary use, as with URLs, is to separate directory and file components of a path:

pictures/image.jpg

http://en.wikipedia.org/wiki/Slash_%28punctuation%29

A leading slash however represents the root directory of the virtual file system; it is used when specifying absolute paths:

/home/joe/pictures/image.jpg

It is sometimes called a "forwardslash" to contrast with the backslash \, which is the path delimiter on MS-DOS and Microsoft Windows systems. These operating systems use the backslash rather than the slash because in the early days of CP/M—before directories were supported —the slash was chosen as the command-line option indicator:

dir /w /ogn

Note however that the "forward slash" will be translated into a backslash by most versions of DOS and Windows, in contexts where there is little ambiguity with command-line options. Some people incorrectly refer to a slash as a "backslash", for instance when reading URLs out loud.

Chat

Many Internet Relay Chat and in-game chat clients use the slash to distinguish commands, such as the ability to join or part a chat room or send a private message to a certain user.

/join #services – to join channel "#services"

/me sings a song about birds.

Programming

In computer programming, the solidus corresponds to Unicode and ASCII character 47, or 0x002F. It is used in the following settings:

• In most programming languages, / is used as a division operator,
• Comments in C, C++, CSS and Java begin with /* (a slash and an asterisk), and end with */ (the same characters in the opposite order).
• C99, C++, and Java also have comments that begin with // (two slashes) and span a single line.
• In HTML and XML, a slash is used to indicate a closing tag. For example, in HTML, </em> ends a section of emphasized text that had been started with <em>.
• Slashes are used as the standard delimiters for regular expressions, although other characters can be used instead.
• Slashes are sometimes used to show italics, when no special formatting is available. Example: /Italic text/

Dates

Certain shorthand date formats use / as a delimiter, for example "9/16/2003" (in United States usage) or in most other countries "16/9/2003" September 16, 2003.

In Britain there was a specialized use in prose: 7/8 May referred to the night which starts the evening of 7 May and ends the morning of 8 May, totalling about 12 hours depending on the season. This was used to list night-bombing air-raids which would carry past midnight. Some police units in the US use this notation for night disturbances or chases. Conversely, the form with a hyphen, 7-8 May, would refer to the two-day period, at most 49 hours. This would commonly be used for meetings.

The International Standard ISO 8601, in attempting to resolve this ambiguity, introduced problems of its own. According to this norm, dates must be written year-month-day using hyphens, but time periods are written as two standard dates separated by a slash: 1939-09-01/1945-05-08, for example, would be the duration of the Second World War in the European theatre, while 09-03/12-22 might be used for a fall term of a Western school, from September third to December twenty-second.

Fiction

The slash has been used as the title of a novel by Greg Bear, / (Slant). The "Slant" was added on to give people something to call the book, but it has ultimately become the accepted title in many book lists.

The Slash is also the symbol for a wand in NetHack.

For a specialized use of the slash in the titles of fan fiction stories, see slash fiction.

Linguistics

Slashes are used to enclose a phonemic transcription of speech.

Physics

In physics, a slash through a symbol, like is shorthand for a^μγ_μ

Proofreading

When highlighting corrections on a proof, a copy editor will either write what he thinks should be changed—or why it should be changed—in the margin. He separates his comments with a slash called a separatrix.

In addition, when marking an uppercase letter for conversion to lowercase, an editor will put a slash through it and write lc or l/c in the margin.

Other alternations with hyphen

Besides the varied usage with dates, the slash is used to indicate a range of serial numbers which have the hyphen already as part of their alphanumeric symbol set. The primary example is the US Air Force serial numbers for aircraft. These are usually written, for example, as "85-1000", for the thousandth aircraft ordered in fiscal year 1985 (which appears on the tail of the aircraft as 51000, it being assumed that the aircraft will be worn out by 1995). To designate a series of serial numbers, the slash is used thuswise: 85-1001/1050 for the first fifty subsequent aircraft.

Alternative names

Sometimes the slash is called stroke (and oblique stroke) , although that may be confused with the hyphen. Stroke is most commonly used among the North American amateur radio community.

 

External links

• Grammatically Correct – Using Slashes Correctly