Help:Special characters: Difference between revisions

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From MediaWiki 1.5, all projects use Unicode (UTF-8) character encoding. Many characters, including CJK characters, can be in the wikitext itself. They use a variable number of bytes per character.

Important special characters

Umlauts and accents: À Á Â Ã Ä Å Æ Ç È É Ê Ë Ì Í Î Ï Ñ Ò Ó Ô Œ Õ Ö Ø Ù Ú Û Ü ß à á â ã ä å æ ç è é ê ë ì í î ï ñ ò ó ô œ õ ö ø ù ú û ü ÿ

Punctuation: ¿ ¡ « » § ¶ † ‡ • - – —

Commercial symbols: ™ © ® ¢ € ¥ £ ¤

Greek characters: α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ σ ς τ υ φ χ ψ ω Γ Δ Θ Λ Ξ Π Σ Φ Ψ Ω

Math characters: ∫ ∑ ∏ √ − ± ∞ ≈ ∝ ≡ ≠ ≤ ≥ × · ÷ ∂ ′ ″ ∇ ‰ ° ∴ ø ∈ ∩ ∪ ⊂ ⊃ ⊆ ⊇ ¬ ∧ ∨ ∃ ∀ ⇒ ⇔ → ↔ ↑ ℵ ∉ °

For more, see w:Table of mathematical symbols.

Subscripts and superscripts as special characters (here shown with x): x₀ x₁ x₂ x₃ x₄ x₅ x₆ x₇ x₈ x₉ x⁰ x¹ x² x³ x⁴ x⁵ x⁶ x⁷ x⁸ x⁹

Compare, as alternative and for other sub- and superscripts:

xk → x_k [1]
xk → x^k [2]
{{#tag:math|x_k}} → $x_{k}$ [3]
{{#tag:math|x^k}} → $x^{k}$ [4]

Editing

Ways to enter a non-ASCII character into the wikitext:

Use a link to a special character listed under the edit box to insert that character. Wikis need Extension:CharInsert for this. Which characters are displayed depends on the wiki, and on user preference settings; sometimes lists are collapsible, or there is a menu to select a list.
Copy the character from some list on a webpage, like that above, or from a locally stored page. The character should not be an image or part of an image, hence for example not an image produced by the TeX feature of the wiki. Thus one can copy for example from the characters in the first column of w:Table of mathematical symbols.
Use a special keyboard function (or enter the character directly from a foreign keyboard).
Use a special browser function.
Use an HTML named character entity reference like à or HTML numeric character reference like ¡, and copy the character from preview. In the past the code itself had to be stored in the wikitext. Such codes may still be present on some pages. Results of the internal search function may be affected by this. On the other hand, this search function cannot find some characters, including "→", while if it is coded as "→", it can be found by searching for "rarr". See also Help:Searching.

Esperanto

in edit box	in database and output
S	S
Sx	Ŝ
Sxx	Sx
Sxxx	Ŝx
Sxxxx	Sxx
Sxxxxx	Ŝxx

MediaWiki installations configured for Esperanto use UTF-8 for storage and display. However when editing the text is converted to a form that is designed to be easier to edit with a standard keyboard.

The characters for which this applies are: Ĉ, Ĝ, Ĥ, Ĵ, Ŝ, Ŭ, ĉ, ĝ, ĥ, ĵ, ŝ, and ŭ. You may enter these directly in the edit box if you have the facilities to do so. However when you edit the page again you will see them encoded as Sx. This form is referred to as "x-sistemo" or "x-kodo". In order to preserve round trip capability when one or more x's follow these characters or their non-accented forms (C, G, H, J, S, U, c, g, h, j, s, u), the number of x's in the edit box is double the number in the actual stored article text.

For example, the interlanguage link [[en:Luxury car]] to en:Luxury car has to be entered in the edit box as [[en:Luxxury car]] on eo:. This has caused problems with interwiki update bots in the past.

Browser issues

Some browsers are known to do nasty things to text in the edit box. Most commonly they convert it to an encoding native to the platform (whilst the NT line of Windows is internally UCS-2LE (2 Byte subset of UTF-16) it has a complete duplicate set of APIs in the Windows ANSI code page and many older apps tend to use these, especially for things like edit boxes). Then they let the user edit it using a standard edit control and convert it back. The result is that any characters that do not exist in the encoding used for editing get replaced with something that does (often a question mark though at least one browser has been reported to actually transliterate text!).

IE for the Mac

This relatively common browser translates to mac-roman for the edit box with the result it munges most Unicode stuff (usually but not always by replacing them with a question mark). It also munges things that are in ISO-8859-1 but not mac-roman (specifically ¤ ¦ ¹ ² ³ ¼ ½ ¾ Ð × Ý Þ ð ý þ and the soft hyphen) so the problems it causes are not limited to Unicode wikis (though they tend to be much worse on Unicode wikis because they affect actual text and interwiki links rather than just fairly obscure symbols).

Netscape 4.x

Similar issues to IE Mac though the character set converted to and from will obviously not always be mac-roman.

Console browsers

Lynx, Links (in text mode) and W3M convert to the console character set (Lynx and Links actually using a transliteration engine) for editing and convert back on save. If the console character set is UTF-8 then these browsers are Unicode safe but if it isn't they aren't. With Lynx and Links a possible detection method would be to add another edit box to the login form but this won't work for W3M as it doesn't convert the text to the console character set until the user actually attempts to edit it.

The workaround

In database and edit box for normal browsers	In editbox for trouble browsers
œ	œ
œ	œ
œ	œ

After English Wikipedia switched to UTF-8 and interwiki bots started replacing html entities in interwikis with literal unicode text, edits that broke unicode characters became so common they could no longer be ignored. A workaround was developed to allow the problematic browsers to edit safely provided that MediaWiki knew they have problems.

Browsers listed in the setting $wgBrowserBlackList (a list of regexps that match against user agent strings) are supplied text for editing in a special form. Existing hexadecimal html entities in the page have an extra leading zero added, non-ascii characters that are stored in the wikitext are represented as hexadecimal html entities with no leading zeros.

Currently the default settings only have IE mac and a specific version of netscape 4.x for linux in the blacklist. Nevertheless it seems to have stopped most of the problem.

Viewing

Most current browsers have some level of Unicode support but some do it better than others. The most commonly encountered problem is that Internet Explorer relies on preconfigured font links in the registry rather than actually searching for a font that can display the character in question. This means that Internet Explorer often has to be forced to use particular fonts. On English Wikipedia there are a set of templates to do this. For example {{unicode}} for general Unicode text, {{polytonic}} for polytonic Greek and {{IPA}} for the International Phonetic Alphabet. The stuff in Windows Glyph List 4 should be safe to use without such special measures.

... may work, but only for people with that font.

Displaying special characters

To display Unicode or special characters on web page(s), one or more of the Unicode fonts need to be present or installed in your computer, first. For proper working functionality, setup or configuration or settings from the web page viewing browser software also needs to be modified.

The default font for Latin scripts in Internet Explorer(IE) web browser for Windows is Times New Roman. It doesn't include many Unicode blocks. To properly view special characters in IE, you must set your browser font settings to a font that includes many Unicode blocks of characters, such as Lucida Sans Unicode font, which comes with Windows XP, DejaVu Sans, TITUS Cyberbit, GNU Unifont which are freely available, or Arial Unicode MS, which comes with Microsoft Office. See subsection below for specific instructions.

Alternatively, the style sheet page related to the web page(s), could also try using Unicode-range specifications to note the gaps where Times New Roman does not have glyphs from Unicode blocks, such as, Hawaiian ‘okina (glottal stop), etc. and thus force the browser to check further down the list of next fonts to try to display those special characters.

Special symbols should display properly without further configuration with Mozilla Firefox, Konqueror, Opera, Safari and most other recent browsers. An optional step can be taken for better (and correct) display of characters with ligature forms, combined characters, after the previously mentioned steps were followed, is to install a rendering engine software.

To use one of the available Unicode fonts for displaying special characters inside a table or chart or box, specify the class="Unicode" in the table's TR row tag (or, in each TD tag, but using it in each TR is easier than using it in each TD), in wiki table code, use that after the (TR equivalent) "|-" (like, |- class="Unicode").

For displaying individual special character, template code {{Unicode|char}} for each character can be used. HTML decimal or hexadecimal numeric entity codes can be used in the place of the char. If a paragraph with lots of special Unicode characters need to be displayed, then,  ... , or,  ...  code can also be used.

The class="Unicode" is to be used in web page(s), HTML or wiki tags, where various characters from wide range of various Unicode blocks need to be displayed. If the special characters that need to be displayed on web page(s), are mostly covering fewer Unicode blocks, related to latin scripts, then class="latinx" can be used. For special characters or symbols related to International Phonetic Alphabet, class="IPA" can be used. For polytonic (Greek) characters or related symbols, class="polytonic" can be used.

Changing Internet Explorer's (IE) default font

From the IE menu bar, follow this path: Tools -> Internet Options -> Fonts -> Webpage Font:
to a scrolling list of fonts. As indicated above, the default selection for Windows is Times New Roman. For viewing of many special characters, select a different font, such as Lucida Sans Unicode, and then select OK.

Linking text with special characters

Many users have settings giving underlined links. When linking a special character, in some cases the result may be mistaken for another character with a different meaning:

Linking + − < > ⊂ ⊃ gives + − < > ⊂ ⊃ which may look like ± = ≤ ≥ ⊆ ⊇. In such cases one can better use a separate link:

A ⊂ B (see subset)

There is less risk of confusion if more than one character is linked, e.g. x > 3.

Alt keycodes

See also : Alt codes, Windows Alt keycodes

Many special characters which have decimal equivalent codepoint numbers that are below 256, can be typed in by using the keyboard's Alt + Decimal equivalent code numbers keys.

For example, the character é (Small e with acute accent, html entity code "é") can be obtained by pressing Alt + 130.

Which means, first press the "Alt" key and keep on pressing it (or keep on holding it), with your left hand, then press the digit keys 1, 3, 0, in sequence, one by one, in the right-side Numeric Keypad part of the keyboard, then release the Alt key.

But special characters, for example, λ (small lambda) cannot be obtained from its decimal code 955 or 0955, by using it with the Alt key, if used inside Notepad or Internet Explorer (IE). You'll get wrong character "╗" or "»".

The "Wordpad" (Windows Operating system) editor accepts the decimal (numeric entity codepoints) values above 256, so it can be used to obtain the Special/Unicode characters, then copy-paste where you need.

To obtain such special characters correctly, which have decimal codepoint values above the 256, another option is to use or type its hex equivalent codepoint first, then press Alt+X keys. To do this, open or start Wordpad, Word, etc editing application software, (this Alt+X process will not work in Internet Explorer, Notepad, etc). Type in 3BB, which is a hexadecimal equivalent numeric codepoint of the character λ, then press Alt+X. Hexcode 3BB will convert/turn into the λ character. If you press the Alt+X key combination again, then λ character will convert back to its hex equivalent codepoint, 3BB. Now character(s) can be copy pasted, where you want to use, or, (in IE) use its html hexadecimal equivalent code λ or its html decimal equivalent code λ.

Characters and formulas which are not directly entered as wikitext

xk → x_k [5]
xk → x^k [6]

Alternative wikitext for characters that can directly be entered as wikitext:

→ gives →, etc.

Characters and formulas displayed as image

Displaying additional characters and also formulas:

For example: {{#tag:math|\sqrt x}} → ${\sqrt {x}}$ [7]

A user preference setting controls to what extent HTML code is used, if possible, and to what extent images. See Help:Displaying a formula.

Egyptian hieroglyphs:

For example: {{#tag:hiero|a-p:t-q}} →

[8]

See mw:Extension:WikiHiero/Syntax.

External links

http://www.unicode.org/charts/ Unicode character charts; hexadecimal numbers only; PDF files showing all characters independent of browser capabilities
http://www.unicode.org/help/display_problems.html Help for enabling Unicode support on most platforms
Table of Unicode characters from 1 to 65535 - shows how the decimal character references look in one's browser
HTML 4.0 Character Entity References - shows how the named and decimal character references look in one's browser
FileFormat.Info - details of many Unicode characters, including the named, decimal and hexadecimal character reference, showing how it should look and for each, how it looks in one's browser
Alan Wood's Unicode Resources - comprehensive resource with character test pages for all Unicode ranges, as well as OS-specific Unicode support information and links to fonts and utilities.
CharacterPal - Free Mac OS X Dashboard Widget that displays key combinations for special characters.
A convertor that helps you find the right escape sequence to use - helps when you need to escape ASCII/Unicode characters that are special characters in wiki markup

Links to other help pages

Help contents: Meta · Wikinews · Wikipedia · Wikiquote · Wiktionary · Commons: · Wikidata · MediaWiki · Wikibooks · Wikisource · MediaWiki: Manual · Google
Versions of this help page (for other languages see further): What links here on Meta or from Meta · Wikipedia · MediaWiki
Reading: Go · Search · Namespace · Page name · Section · Backlinks · Redirect · Category · Image page · Special pages · Printable version
Tracking changes: Recent changes (enhanced) | Related changes · Watching pages · Diff · Page history · Edit summary · User contributions · Minor edit · Patrolled edit
Logging in and preferences: Logging in · Preferences
Editing: Starting a new page · Advanced editing · Editing FAQ · Export · Import · Shortcuts · Edit conflict · Page size
Referencing: Links · URL · Interwiki linking · Footnotes
Style and formatting: Wikitext examples · CSS · Reference card · HTML in wikitext · Formula · Lists · Table · Sorting · Colors · Images and file uploads
Fixing mistakes: Show preview · Reverting edits
Advanced functioning: Expansion · Template · Advanced templates · Parser function · Parameter default · Magic words · System message · Substitution · Array · Calculation · Transclusion
Others: Special characters · Renaming (moving) a page · Preparing a page for translation · Talk page · Signatures · Sandbox · Legal issues for editors

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