Editing Encyclopedia:Manual of Style (section)

===Controlling line breaks<span id="Non-breaking spaces"></span>===
{{Shortcut|MOS:NBSP}}
{{See also|Help:Line-break handling|Template:Spaces}}

It is sometimes desirable to force a text segment to appear entirely on a single line{{mdashb}}that is, to prevent a line break (line wrap) from occurring anywhere within it.
*A '''[[non-breaking space]]''' (or '''hard space''') will never be used as a line-break point. Markup: for {{xt|19{{nbsp}}kg}}, code <code>19&amp;nbsp;kg</code> {{em|or}} <code>19{{t|nbsp}}kg</code>.
*Or use {{tlx|nowrap}}, {{tlx|nobreak}}, or {{tlx|nobr}} (all equivalent). Markup: for {{xt|{{nobr|5° 24′ N}}}}, code {{tlx|nobr|5° 24′ N}}.

It is desirable to prevent line breaks where breaking across lines might be confusing or awkward. For example:
{{columns list|colwidth=15em|
*<code>17{{t|nbsp}}kg</code>
*<code>AD{{t|nbsp}}565</code>
*<code>2:50{{t|nbsp}}pm</code>
*<code>£11{{t|nbsp}}billion</code>
*<code>May{{t|nbsp}}2014</code>
*{{tlx|nobr|5° 24′ 21″ N}}
*<code>Boeing{{t|nbsp}}747</code>
*<code>123{{t|nbsp}}Elm Street</code>
*<code>World War{{t|nbsp}}II</code>
*<code>Pope Paul{{t|nbsp}}VI</code>
*<code><nowiki>''</nowiki>E.{{t|nbsp}}coli<nowiki>''</nowiki></code>
}}

Whether a non-breaking space is appropriate depends on context: whereas it is appropriate to use <code>12{{t|nbsp}}MB</code> in prose, it may be counterproductive in a table (where an unattractive break may be acceptable to conserve precious horizontal space) and unnecessary in a short parameter value in an infobox (where a break would never occur anyway).

A line break may occur at a '''thin space''' (<code>&amp;thinsp;</code>, or {{tlx|thinsp}}), which is sometimes used to correct too-close placement of adjacent characters. An undesirable line break may also occur at special characters such as in ''bit/s''. To prevent these, consider using {{tlx|nobr}} e.g. {{tlx|nobr|100 Mbit/s}}.

Insert non-breaking and thin spaces as [[named character reference]] (<code>&amp;nbsp;</code> or <code>&amp;thinsp;</code>), or as templates that generate these ({{tlx|nbsp}}, {{tlx|thinsp}}), and never by entering them directly into the edit window from the keyboard{{snd}}they are visually indistinguishable from regular spaces, and later editors will be unable to see what they are. Inside wikilinks, a construction such as {{nobr|<code><nowiki>[[World War&amp;nbsp;II]]</nowiki></code>}} works but {{nobr|<code>[[World War{{t|nbsp}}II]]</code>}} doesn't.