In word processing and digital typesetting, a non-breaking space, also known as a no-break
space or non-breakable space, is a variant of the space character that prevents an automatic
line break at its position. In certain formats, it also prevents the “collapsing”
of multiple consecutive whitespace characters into a single space. The non-breaking space
is also known as a hard space or fixed space. In Unicode, the "common" non-breaking space
is encoded as U+00A0 no-break space. Other width variations also exist.
Uses and variations Despite having similar layout and uses with
whitespace, it differs in contextual behavior. Non-breaking behavior
Text-processing software typically assumes that an automatic line break may be inserted
anywhere a space character occurs; a non-breaking space prevents this from happening. For example,
if the text "100 km" will not quite fit at the end of a line, the software may insert
a line break between "100" and "km". To avoid this undesirable behaviour, the editor may
choose to use a non-breaking space between "100" and "km". This guarantees that the text
"100 km" will not be broken: if it does not fit at the end of a line it is moved in its
entirety to the next line. Non-collapsing behavior
A second common application of non-breaking spaces is in plain text file formats such
as SGML, HTML, TeX and LaTeX, which treat sequences of whitespace characters as if they
were a single character. Such "collapsing" of whitespace allows the author to neatly
arrange the source text using line breaks, indentation and other forms of spacing without
affecting the final typeset result. In contrast, non-breaking spaces are not merged
with neighboring whitespace characters when displayed, and can therefore be used by an
author to insert additional visible space in the resulting output. Conversely, indiscriminate
use, in addition to a normal space, gives extraneous extra space in the output.
Width variation Other non-breaking variants, defined in Unicode:
U+2007 figure space. Produces a space somewhat equal to the figures characters.
U+202F narrow no-break space. It was introduced in Unicode 3.0 for Mongolian, to separate
a suffix from the word stem without indicating a word boundary. Also required for French
and Russian punctuation. U+2060 word-joiner: encoded in Unicode since
version 3.2. The word-joiner does not produce any space and prohibits a line break on either
side of it. As its name more clearly suggests, it is a non-breaking word separator.
Encodings Unicode defines several other non-break space
characters. See #Width variation. Encoding remarks:
Word joiner, encoded in Unicode 3.2 and above as U+2060, and in HTML as ⁠ or ⁠.
The Byte Order Mark, U+FEFF, officially named "Zero Width No-Break Space", can also be used
with the same meaning as the word joiner, but in current documents this use is deprecated.
See also Zero-width non-breaking space. Keyboard entry methods
It is rare for national or international standards on keyboard layouts to define an input method
for the non-breaking space. An exception is the Finnish multilingual keyboard, accepted
as the national standard SFS 5966 in 2008. According to the SFS setting, the non-breaking
space can be entered with the key combination AltGr + Space.
Typically, authors of keyboard drivers and application programs have devised their own
keyboard shortcuts for the non-breaking space. For example:
Apart from this, applications and environments often have methods of entering unicode entities
directly via their code point, e.g. via the Alt Numpad input method. in codepage 437 and
codepage 850, and codepoint 160 decimal in codepage 1252.)
See also Hyphens in computing, for information about
hard and non-breaking hyphens List of XML and HTML character entity references
Orphans and widows Punctuation
Sentence spacing in digital media Space
References ^ "Justify Just or Just Justify", M. Elyaakoubi
and A. Lazrek. Journal of Electronic Publishing, vol. 13, issue 1, 2010.
DOI 10.3998/3336451.0013.105. ^ http:www.chicagomanualofstyle.orgdatatopics/SpecialCharacters.html
^ "Structure", HTML 4.01, W3, 1999-12-24 . ^ "Text", CSS 2.1, W3 .
^ Kotoistus, Uusi näppäinasettelu [Status of the new keyboard layout], CSC – IT Center
for Science . Drafts of the Finnish multilingual keyboard.