Help:Special characters: Difference between revisions

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Systems for character encoding

From MediaWiki 1.5, all projects use Unicode (UTF-8) character encoding.

Until the end of June 2005, when this new version came into use on Wikimedia projects, the English, Dutch, Danish, and Swedish Wikipedias used windows-1252 (they declared themselves to be ISO-8859-1 but in reality browsers treat the two as synonmous and the mediawiki software made no attempt to prevent use of stuff from windows-1252). Pre-upgrade wikitext in thier databases remains stored in windows-1252 and is converted on load. Edits made since the upgrade will be stored as UTF-8 in the database. This conversion on load process is invisible to users.

Unicode (UTF-8)
- a variable number of bytes per character
- special characters, including CJK characters, can be treated like normal ones; not only the webpage, but also the edit box shows the character; in addition it is possible to use the multi-character codes; they are not automatically converted in the edit box.
ISO 8859-1
- one byte per character
- special characters that are not available in the limited character set are stored in the form of a multi-character code; there are usually two or three equivalent representations, e.g. for the character € the named character reference € and the decimal character reference € and the hexadecimal character reference €. The edit box shows the entered code, the webpage the resulting character. Unavailable characters which are copied into the edit box are first displayed as the character, and automatically converted to their decimal codes on Preview or Save.
- the most common special characters, such as é, are in the character set, so code like é, although allowed, is not needed.

Note that Special:Export exports using UTF-8 even if the database is encoded in ISO 8859-1, at least that was the case for the English Wikipedia, already when it used version 1.4.

To find out which character set applies in a project, use the browser's "View Source" feature and look for such as this:

<meta http-equiv="Content-type" content="text/html; charset=iso-8859-1" />

or

<meta http-equiv="Content-type" content="text/html; charset=utf-8" />

Esperanto

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, 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 (A, 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.

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

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.

Ways to enter special characters

Many characters not in the repertoire of standard ASCII will be useful—even necessary—for wiki pages, especially for foreign language textbooks. This page contains recommendations for which characters are safe to use and how to use them. There are three ways to enter a non-ASCII character into the wikitext:

Enter the character directly from a foreign keyboard, or by cut and paste from a "character map" type application, or by some special means provided by the operating system or text editing application. Some browsers will change characters outside the charset of the wiki into html numeric charater entities (see below).
Use an HTML named character entity reference like à. This is unambiguous even when the server does not announce the use of any special character set, and even when the character does not display properly on some browsers. However, it may cause difficulties with searches (see below).
Use an HTML numeric character entity reference like ¡. Unfortunately some old browsers incorrectly interpret these as references to the native character set. It is, however, the only way to enter Unicode values for which there is no named entity, such as the Turkish letters. Note that because the code points 128 to 159 are unused in both en:ISO-8859-1 and Unicode, character references in that range such as  are illegal and ambiguous, though they are commonly used by many web sites. (Note they are not technically unused, but they map to rare control codes that are illegal in html.) Also note that almost all browsers treat iso-8859-1 as windows-1252, which does have printable characters in that space, and they often find their way into article titles on en, which really causes confusion when trying to create interwiki links to said pages.

Generally speaking, Western European languages such as Spanish, French, and German pose few problems. For specific details about other languages, see: Turkish. (More will be added to this list as contributors in other languages appear.)

For the purpose of searching, a word with a special character can best be written using the first method. If the second method is used a word like Odiliënberg can only be found by searching for Odili, euml and|or nberg; this is actually a bug that should be fixed—the entities should be folded into their raw character equivalents so all searches on them are equivalent. See also Help:Searching.

External links

http://www.unicode.org/charts/ Unicode character charts; hexadecimal numbers only; PDF files showing all characters independent of browser capabilities
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.

Links to other help pages

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Advanced functioning: Expansion · Template · Advanced templates · Parser function · Magic words · System message · Substitution · Arrays · Expr parser function syntax · Transclusion
Others: Special characters · Renaming (moving) a page · Preparing a page for translation · Talk pages · Signatures · Sandbox · Legal issues for editors

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