Space (punctuation)

In writing, a space ( ) is a blank area devoid of content, serving to separate words, letters, numbers, and punctuation. Conventions for interword and intersentence spaces vary among languages, and in some cases the spacing rules are quite complex. In the classical period, Latin was written with interpuncts (centred dots) as word separators, but that practice was abandoned sometime around 200 AD in favour of scriptio continua, i.e., with the words running together without any word separators. In around 600–800 AD, blank spaces started being inserted between words in Latin, and that practice carried over to all languages using the Latin alphabet (including English and most other Western European languages).

In typesetting, spaces have historically been of multiple lengths with particular space-lengths being used for specific typographic purposes, such as separating words or separating sentences or separating punctuation from words. Following the invention of the typewriter and the subsequent overlap of designer style-preferences and computer-technology limitations, much of this reader-centric variation was lost in normal use.

In computer representation of text, spaces of various sizes, styles, or language characteristics (different space characters) are indicated with unique code points. Whitespace characters include the various types of spaces, tabs, line breaks, paragraph breaks, page breaks, and related characters. These are used in digital typesetting, inputting commands, programming, and markup languages.

Use of the space in natural languages

Spaces between words

Main article: Word divider

Modern English uses a space to separate words, but not all languages follow this practice. Spaces were not used to separate words in Latin until roughly 600–800 AD. Ancient Hebrew and Arabic did use spaces, partly to compensate in clarity for the lack of vowels. Traditionally, all CJK languages have no spaces: modern Chinese and Japanese (except when written with little or no kanji) do not, on the other hand modern Korean uses spaces.

Runic texts use either an interpunct-like or a colon-like punctuation mark to separate words. There are two Unicode characters dedicated for this: U+16EB ᛫ RUNIC SINGLE PUNCTUATION and U+16EC ᛬ RUNIC MULTIPLE PUNCTUATION.

Spaces between sentences

Main article: Sentence spacing

Languages with a Latin-derived alphabet have used various methods of sentence spacing since the advent of movable type in the 15th century.

• One space (French spacing). This is a common convention in most countries that use the ISO basic Latin alphabet for published and final written work, as well as digital (World Wide Web) media. Web browsers usually do not differentiate between single and multiple spaces in source code when displaying text, unless text is given a "white-space" CSS attribute. Without this being set, collapsing strings of spaces to a single space allows HTML source code to be spaced in a more readable way, at the expense of control over spacing of the rendered page.

• Double space (English spacing). It is sometimes claimed that this convention stems from the use of the monospaced font on typewriters. However, instructions to use more spacing between sentences than words date back centuries, and two spaces on a typewriter was the closest approximation to typesetters' previous rules aimed at improving readability. Wider spacing continued to be used by both typesetters and typists until the Second World War, after which typesetters gradually transitioned to word spacing between sentences in published print, while typists continued the practice of using two spaces.

• One widened space, typically one-and-a-third to slightly less than twice as wide as a word space. This spacing was sometimes used in typesetting before the 19th century. It has also been used in other non-typewriter typesetting systems such as the Linotype machine and the TeX system. Modern computer-based digital fonts can adjust the spacing after terminal punctuation as well, creating a space slightly wider than a standard word space.

• No space. According to Lynne Truss, "young people" today using digital media "are now accustomed to following a full stop with a lower-case letter and no space".

There has been some controversy regarding the proper amount of sentence spacing in typeset material. The Elements of Typographic Style states that only a single word space is required for sentence spacing since "Larger spaces...are themselves punctuation."

Spaces and unit symbols

The International System of Units (SI) recommends inserting a space between a number and a unit of measurement units and between units in compound units, but never between a prefix and a base unit.

5.0 cm not 5.0cm or 5.0 c m

45 kg not 45kg or 45 k g

32 °C not 32°C or 32° C

20 kN m not 20 kNm or 20 k Nm

50 % not 50% (Note:  % is not an SI unit, and many style guides do not follow this recommendation)

The only exception to this rule in the SI the symbolic notation of angles: degree (e.g. 30°), minute of arc (e.g. 22′), and second of arc (e.g. 8″).

See also

• Em (typography)
• En (typography)
• Halfwidth and fullwidth forms
• Internal field separator
• Sentence spacing in digital media
• Types of spaces
  • Figure space
  • Non-breaking space
  • Paren space
  • Thin space
  • Zero-width space
  • Hair space

External links

• Unicode spaces, by Jukka "Yucca" Korpela
• Commonly confused characters