You can use some limited wildcards if you really want to. Look up "fulltext search" on http://www.mysql.com/ and look down under 'boolean search' for the details. However, wildcard searches are slower, so go easy on the poor server.
In a search for a word with a diaeresis, such as Sint Odiliënberg, it depends whether this ë is stored as one character or as "ë". In the first case one can simply search for Odilienberg (or Odiliënberg); in the second case it 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 Wikipedia:Special characters.
If a word appears in an article with single quotes, you can only find it if you search for the word with quotes. Since this is rarely desirable, it is better to use double quotes in articles for which this problem does not arise. See the manual of style for more info.
An apostrophe is identical to a single quote, therefore the name Mu'ammar can be found only by searching for exactly that (and not otherwise). A word with 's is an exception in that it can be found also by searching for the word without the apostrophe and the s.
The search only applies to the namespaces selected in the user's preferences. To search the other namespaces check or uncheck the tickboxes in "Search in namespaces" box found at the bottom of a search results page. Depending on the browser, a box may still be checked from a previous search, but without being effective any longer! To make sure, uncheck and recheck it.
Searching the image namespace means searching the image descriptions, i.e. the first parts of the image description pages.
The source text (what one sees in the edit box, also called wiki text) is searched. This distinction is relevant for piped links, for Wikipedia:interlanguage links (to find links to Chinese articles, search for zh, not for Zhongwen), special characters (if ê is coded as ê it is found searching for ecirc), etc.
外邊有好多搜索引擎能夠提供題材主導嘅搜索, which lets you search Wikipedia specifically. Searches are based on the text as shown by the browser, so wiki markup is irrelevant. Depending on your browser, you may also be able to use tools that allow you to search Wikipedia using bookmarklets.
In general, external search engines are faster than a Wikipedia search. However, because the search engine's cache is based on when the site was indexed, the search may not return newly created pages. Similarly, the search engine's cached version of the page will not be as up-to-date as the link to Wikipedia itself. Also, when returning Wikipedia articles in a regular search, mirrors and forks of Wikipedia content frequently rank higher than the actual Wikipedia articles because of search engine optimization techniques.
These issues may be less of a problem when using certain search engines that process Wikipedia differently:
Yahoo! includes Wikipedia as part of its content acquisition program and gets a regular datafeed.
Clusty downloads and processes the database regularly, generating automatic abstracts and image thumbnails and meaningfully parsing redirects, disambiguations, and categories.
Qwika only indexes wikis, and thus mirrors do not appear in their results.
If you frequently search via Clusty, consider installing the Clusty Toolbar (beta). Selecting the "Encyclopedia" search source allows you to quickly search the English version of Wikipedia. The Clusty Toolbar is available for Windows with Internet Explorer and Mozilla Firefox (beta).
If you frequently search via Google, consider installing the Google Toolbar. Using the "search this site" button allows you to quickly search the English version of Wikipedia. The official Google Toolbar is for Internet Explorer (Windows and Mac) and for Firefox (works on all operating system platforms for which Firefox is available, such as Windows, Linux and Mac OS X).
§How to provide a link to a specific Google Search
Wikipedia markup allows you to insert links to Google searches by including google: as the prefix for the link. This can be useful on talk pages, and sometimes in External link sections. It is done like this:
Note: It is important not to use spaces in the search. To add more parameters to the search, separate them by a plus sign, +. For a phrase search, use a hyphen (minus sign), -, between each word. E.g. to search for "Tip of the day", use Tip-of-the-day.
To provide a link to a Wikipedia-specific search, include in the google-link +site:en.wikipedia.org (no spaces before or after), like this:
There is a full-featured advanced search engine at Lycos UK. It is more powerful than Wikipedia's search box, and you can limit searches to a specific URL, such as the Wikipedia website. Here's how. Click on the provided link above, and then enter your search term. Then scroll down to the domain section and add "wikipedia.org" in the box provided. Then click "Go".
The above languages machine translated into English.
This can assist editors contributing to non-English Wikipedias by being able to search in their own language across the entire English version and then view the machine-translated version in their language.
If you frequently search via Yahoo!, consider installing the Yahoo! Companion Toolbar. Using the "Search Only the Current Site" button allows you to quickly search the English version of Wikipedia. The official Yahoo! Companion Toolbar is only for Windows with Internet Explorer and Mozilla.
§Search Wikipedia from the sidebar search tab or address bar
Works with: Mozilla Suite, Mozilla Firefox, Netscape 6/7.
Mozilla and Netscape 6 & 7 come with a sidebar that allows a user to search the Wikipedia site, and Firefox has a toolbar item to do the same. To install the search plugin that tells Mozilla how to search Wikipedia, do the following:
Go to one of the following sources of Wikipedia search plugins. The Mycroft plugins are sometimes out of date, and plugins from the second source may work better.
There are versions for many languages, so pick the language local to your area.
If you can't install the search plugin automatically, the second source above lets you right-click on the plugin and save it to disk, or download a ZIP file containing all available plugins. Save the downloaded .src file in the searchplugins directory where Mozilla is installed and restart the browser to use the new plugin.
To make Wikipedia your default search engine in Mozilla, Beonex Communicator, and Netscape 6/7:
Go to Edit, Preferences.
Expand the Navigator tree and choose Internet Search.
Choose Wikipedia as your default search engine.
With Wikipedia selected as your default engine, searches can be conducted via the search sidebar tab, search box, or the web address bar.
All Opera versions since v6 use a customizable text file called search.ini. This file should only be edited while Opera is not running. The following example replaces one of the existing pre-defined search engines. It is up to the user to avoid conflicts of shortcut key (key=). By default 'w' is taken by the download.com search, so either this or the Wikipedia one should be changed. Furthermore the 'Search Engine ##' should be replaced with a free number: '12' is free by default. The Search.ini editor makes editing trivial (see external link).
[Search Engine ##]
Opera appears to take a copy of the "search.ini" and load it into an internal buffer of some type. After editing the file with your new entry you must change the "File Version" at the top of the file to allow for your changes to be seen in the browser.
Just right-click on the search field you want to create a search with and click "Create search". The following dialog is really simple. You just have to select a name for the search and a search shortcut. It even alerts you if the shortcut you want is already in use.
Go to Tools -> Preferences -> Search and either Add a new search engine, or edit an existing one, such as Download.com. Recommended parameters are:
Since at least Build 8502, more than one character is allowed (Last versions "Key" changed to a "Keyword"), so instead of setting "w" as the keyword, you alternativly could use "wiki", or whatever you like. Although this is not as short and handy, it would save you the replacement of an existing engine.
After downloading the Wikipedia:TomeRaider database one can search the Wikipedia version offline. One can also search for parts of words. To search the text that appears only in the page history, you must export the text to XML format first.
If there is no appropriate page on Wikipedia, consider creating a page, since you can edit Wikipedia right now. Or consider adding what you were looking for to the Requested articles page. Or if you have a question, then see 邊度發問, which is a list of departments where our volunteers answer questions, any question you can possibly imagine.