Editing Encyclopedia:Manual of Style (section)

===Hyphens===
{{Shortcut|MOS:HYPHEN}}

[[Hyphen]]s ({{xt|-}}) indicate conjunction. There are three main uses:
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# In hyphenated personal names ({{xt|John Lennard-Jones}}, {{xt|Omar al-Bashir}}).
# To link [[prefix]]es with their main terms in certain constructions ({{xt|quasi-scientific}}, {{xt|pseudo-Apollodorus}}, {{xt|ultra-nationalistic}}).
#*A hyphen may be used to distinguish between [[homograph]]s ({{xt|re-dress}} means ''dress again'', but {{xt|redress}} means ''remedy'' or ''set right'').
#*There is a clear trend to join both elements in all varieties of English ({{xt|subsection}}, {{xt|nonlinear}}). Hyphenation clarifies when the letters brought into contact are the same ({{xt|non-negotiable}}, {{xt|sub-basement}}) or are vowels ({{xt|pre-industrial}}), or where a word is uncommon ({{xt|co-proposed}}, {{xt|re-target}}) or may be misread ({{xt|sub-era}}, not {{!xt|subera}}). Some words of these sorts are nevertheless common without the hyphen (e.g., {{xt|cooperation}} is more frequently attested than {{xtg|co-operation}} in contemporary English).{{efn|name=recent}}
# To link related terms in [[compound modifier]]s:{{Efn|1=Specifically, compound [[attributive adjective|attributive]]s, which are modifiers of a noun that occur within the [[noun phrase]]. {{crossref|pw=y|(See {{section link|English compound#Hyphenated compound modifiers}}.)}}}}
#*Hyphens can aid ease of reading (that is, they can be {{xt|ease-of-reading}} aids) and are particularly useful in long noun phrases: {{xt|gas-phase reaction dynamics}}. But never insert a hyphen into a proper name ({{xt|Middle Eastern cuisine}}, not {{!xt|Middle-Eastern cuisine}}).
#*A hyphen can help to disambiguate (some {{xt|short-story writers}} are quite tall; {{xt|a government-monitoring program}} is a program that monitors the government, whereas {{xt|a government monitoring program}} is a government program that monitors).
#*Compounds that are hyphenated when used {{em|[[Attributive adjective|attributively]]}} (adjectives before the nouns they qualify: {{xt|a light-blue handbag}}, {{xt|a 34-year-old woman}}) or {{em|[[substantive]]ly}} (as a noun: {{xt|she is a 34-year-old}}) are usually not hyphenated when used {{em|[[Predicative expression|predicatively]]}} (descriptive phrase separated from the noun: {{xt|the handbag was light blue}}, {{xt|the woman is 34 years old}}). Where there would otherwise be a loss of clarity, however, a hyphen may be used in the predicative form as well ({{xt|hand-fed turkeys}}, {{xt|the turkeys were hand-fed}}). Awkward attributive hyphenation can sometimes be avoided with a simple rewording: {{xt|Hawaiian-native species}} → {{xt|native Hawaiian species}}.
#*Avoid using a hyphen after a standard ''{{nowrap|-ly}}'' adverb ({{xt|a newly available home}}, {{xt|a wholly owned subsidiary}}) unless part of a larger compound ({{xt|a slowly-but-surely strategy}}). In rare cases, a hyphen can improve clarity if a rewritten alternative is awkward, but rewording is usually preferable: {{!xt|The idea was clearly stated enough}} can be disambiguated as {{xt|The idea clearly was stated often enough}} or {{xt|The idea was stated with enough clarity}}.
#*A few words ending in ''{{nowrap|-ly}}'' function as both adjectives and adverbs ({{xt|a kindly-looking teacher}}; {{xt|a kindly provided facility}}). Some such dual-purpose words (like {{xt|early}}, {{xt|only}}, {{xt|northerly}}) are not standard ''{{nowrap|-ly}}'' adverbs, because they are not formed by addition of ''{{nowrap|-ly}}'' to an independent current-English adjective. These need careful treatment: {{xt|Early flowering plants appeared around 130&nbsp;million years ago}}, but {{xt|Early-flowering plants risk damage from winter frosts}}; {{xt|only child actors}} (no adult actors) but {{xt|only-child actors}} (actors without siblings).
#*A hyphen is normally used when the adverb ''well'' precedes a participle used attributively ({{xt|a well-meaning gesture}}; but normally {{xt|a very well managed firm}}, because ''well'' itself is modified) and even predicatively, if ''well'' is necessary to, or alters, the sense of the adjective rather than simply intensifying it ({{xt|the gesture was well-meaning}}, {{xt|the child was well-behaved}}, but {{xt|the floor was well polished}}).
#*In some cases, such as {{xt|diode–transistor logic}}, the independent status of the linked elements requires an en dash instead of a hyphen. {{crossref|pw=y|See {{Section link||Dashes}}.}}
#*{{shortcut|MOS:SUSPENDED|MOS:HANGING}}Use a '''[[suspended hyphen]]''' (also called a ''hanging hyphen'') when two compound modifiers are separated ({{xt|two- and three-digit numbers}}; {{xt|a ten-car or -truck convoy}}; {{xt|sloping right- or leftward}}).
#*Values and units used as compound modifiers are hyphenated only where the unit is given as a whole word; when using the unit symbol, separate it from the number with a [[non-breaking space]] (<code>&amp;nbsp;</code>).

<div class="block-indent" style="padding-left: 5em; padding-right: 0; overflow: hidden;"><!--The underlying code adapted from {{block indent}} which doesn't work around wikitables.-->
{| style="background:transparent;color: var( --color-base );"
|-
| {{em|Incorrect:}} || {{!xt|9-mm gap}}
|-
| {{em|Correct:}} || {{xt|9&nbsp;mm gap}} (markup: <code>9&amp;nbsp;mm gap</code>)
|-
| {{em|Incorrect:}}&nbsp; &nbsp; || {{!xt|9&nbsp;millimetre gap}}
|-
| {{em|Correct:}} || {{xt|9-millimetre gap}}
|-
| {{em|Correct:}} || {{xt|12-hour shift}}
|-
| {{em|Correct:}} || {{xt|12&nbsp;h shift}} (markup: <code>12&amp;nbsp;h shift</code>)
|}
</div>

'''Multi-word hyphenated items:''' It is often possible to avoid multi-word hyphenated modifiers by rewording ({{xt|a four-CD soundtrack album}} may be easier to read as {{xt|a soundtrack album of four CDs}}). This is particularly important where converted units are involved ({{xt|the 6-hectare-limit (14.8-acre-limit) rule}} might be possible as {{xt|the rule imposing a limit of six hectares (14.8 acres)}}, and the ungainly {{!xt|4.9-mile (7.9&nbsp;km) -long tributary}} as simply {{xt|4.9-mile (7.9&nbsp;km) tributary}}).

For optional hyphenation of compound '''points of the compass''' such as ''southwest/south-west'', see {{section link||Compass points}}.

Do not use a capital letter after a hyphen except for a proper name following the hyphen: {{xt|Graeco-Roman}} and {{xt|Mediterranean-style}}, but not {{!xt|Gandhi-Like}}. In titles of published works, when given in [[title case]], follow the capitalization rule for each part independently ({{xt|''The Out-of-Towners''}}), unless reliable sources consistently do otherwise in a particular case ({{xt|''The History of Middle-earth''}}).

Hyphenation rules in other languages may be different. Thus, in French a place name such as {{xt|Trois-Rivières}} ('Three Rivers') is hyphenated, when it would not be in English. Follow reliable sources in such cases.

'''Spacing:''' A hyphen is never followed or preceded by a space, except when hanging {{crossref|pw=y|(see above)}} or when used to display parts of words independently, such as {{xt|the prefix sub-}}{{nbsp}}and {{xt|the suffix{{nbsp}}{{nbhyph}}less}}.

'''Image filenames and redirects:''' Image filenames are not part of the encyclopedic content; they are tools. They are most useful if they can be readily typed, so they usually use hyphens instead of dashes. Similarly, article titles with dashes should also have a corresponding redirect from a copy of the title with hyphens: for example, {{xt|[[Michelson-Morley experiment]]}} redirects to {{xt|[[Michelson–Morley experiment]]}}.

'''Non-breaking:''' A [[non-breaking hyphen]] ({{tlx|nbhyph}}) will {{em|not}} be used as a point of line-wrap.

{{Shortcut|MOS:SHY|MOS:SOFTHYPHEN}}
{{Anchor|shy}}
'''Soft hyphens:''' Use [[soft hyphen]]s to mark locations where a word will be broken and hyphenated {{em|if necessary}} at the end of a line of text, usually in [[Longest English words|very long words]] or narrow spaces (such as captions, narrow table columns, or text adjacent to a very wide image), for example: {{tlx|shy|Penn|syl|va|nia and Mass|a|chu|setts style themselves com|mon|wealths.}}. Use sparingly to avoid making wikitext difficult to read and edit. For more information, see [[Help:Line-break handling#%3Cwbr /%3E and soft hyphens|Help:Line-break handling]].

'''Encoding''': The hyphen is represented by the {{small|ASCII/UNICODE [[hyphen-minus|HYPHEN-MINUS]]}} character, which is entered by the hyphen or minus key on all standard keyboards. Do not use the {{small|[[Hyphen#Unicode|UNICODE HYPHEN]]}} character.

Hyphenation involves many subtleties that cannot be covered here; the rules and examples presented above illustrate the broad principles.