The US FDA’s proposed rule on laboratory-developed tests: Impacts on clinical laboratory testing

Sometimes a word means more than one thing, so you might want the same title for two different pages.

To solve this, we disambiguate.

Wikipedia grows very fast because making links is quite simple and natural. When you type in a window for editing, put two brackets on each side of the word (like this: [[Mercury]]) and you will get Mercury. If you do this to a word, you have made it a link.

There are many things called Mercury. Some of these are:

• Mercury (mythology), the Roman god
• Mercury (planet), the first planet from the Sun
• Mercury (element), the chemical element

Mercury can also mean many other things. Which one did you mean to link?

Solving this ambiguity can be done in several ways:

• "Sub-topic" disambiguation: many small articles of just a paragraph or so each can exist together on a single page, separated by headings. However, as each section grows, there comes a time when each article must have its own page.
• "Equal" disambiguation: all articles are moved to distinct names, and the "Mercury" page becomes a disambiguation page: a simple list that points to those specific articles, perhaps explaining the differences among them.
• "Primary topic" disambiguation: if one meaning is clearly predominant, it remains at "Mercury", the general title. The top of the article is given links to the other meanings, or if there are many, to a page named "Mercury (disambiguation)". For example: the page Bat has a link at the top to a page named "Bat (disambiguation)" which lists other things named bat. The page Cream has a link to the page Cream (band) at the top.

Making a disambiguation involves four steps:

1. appropriate (and distinct) titles are chosen for the specific topics
2. the disambiguation page is written
3. any existing links to the general title are replaced by links to the appropriate specific topics
4. a link to the new disambiguation page is added to the appropriate list (see "Links to disambiguation pages", below)

A warning, though: people sometimes have an urge to create disambiguation pages without fixing all the links to them. The result is that Wikipedia is left in a worse state than it was before the page was split.

Before creating a disambiguation page, click on "What links here" to find all the pages that link to the page you are about to change. Make sure those pages are fixed or that they won't be adversely affected before you do the split.

A code of honor for creating disambiguation pages is to fix the misdirected links that will be created when the disambiguation page is made.

For creating the specific topic pages, a few options are available:

• If there's an alternate name or more complete name that is equally clear, it can be used.

For example

1. Java programming language
2. Association football.

• Otherwise, a disambiguating word or phrase can be added in parentheses. The word or phrase in parentheses should be one of two things: a generic noun describing what the specific title is an instance of, for example:

1. Mercury (element)
2. Capital (city)

• It could also be the subject or context to which the term applies, for example:

1. Union (American Civil War)
2. Plane (mathematics).

• Rarely, an adjective describing the title can be used, but in this case it is usually better to rephrase the title to avoid parentheses. If there is a choice between using a short phrase and a word with context (for example, "Mathematical analysis" vs. "Analysis (mathematics)", there is no hard rule about which is preferred, and both can be created, one redirecting to the other.
• A special case of using a "context" to disambiguate is when the context is a book or other creative work, such as with articles about fictional characters. However, Wikipedia does not encourage a lot of twisty short stubs about fictional characters.
• If there is a choice between disambiguating with a generic term or with a context, choose the simpler.

For example:

1. "mythology" rather than "mythological figure".

Use the same disambiguating phrase for topics within the same context.

• To conform to our normal naming conventions, the phrase in parentheses should be treated just as any other word in a title: normally lowercase, unless it is a proper noun that always appears capitalized even in running text (such as a book title).

For more on which word or phrase to insert in the parentheses, see Wikipedia:Naming conventions and Wikipedia talk:Naming conventions.

There is some flexibility in creating the disambiguation page itself, or even whether it is necessary to create one at all. As mentioned earlier, if the title clearly has one central most important meaning, and one or two lesser-known meanings in narrow contexts, it is probably better to have the full article about the primary meaning under the simple title, after brief links to the special uses.

For example, the poker article covers the card game; it is unlikely that there will ever be an encyclopedia article on fireplace pokers, but if we did create one, then we could link to it from the existing poker article without having to move that article to "Poker (game)".

If a disambiguation page is merited, it can be as simple as a bullet list of specific articles with links and perhaps a brief one-line description of each (saving details for the specific articles), or it might have some explanatory text of its own if differences need to be explained, or if there is interesting history of the term itself independent of the specific topics.

The appropriate method will depend on the nature of the subject. The articles below serve as examples of what can be done (and a few examples of what shouldn't be done, but hopefully not many). Note that a disambiguating page may look a lot like a dictionary entry. We try to maintain a policy that Wikipedia is not a dictionary, so please resist the urge to make such pages even more dictionary-like than they already are (for example, there is no need to put parts of speech, plurals or pronunciations, unless those serve to clarify the topics).

You may want to include a note at the bottom of the page, or insert by typing {{disambig}}.

''This is a [[Wikipedia:disambiguation|disambiguation]] page; that is, one that just points to other pages that might otherwise have the same name. If you followed a link here, you might want to go back and fix the link, so that it points to the appropriate page.''

Some people don't understand what such a notice accomplishes, however, and recommend against them. Others recommend a shorter version (one which does not indicate that links to disambiguation pages need "fixing"):

• ''This is a [[Wikipedia:disambiguation|disambiguation]] page; if one followed a link here, one might want to go back and adjust that link.''

If you're not making a whole disambiguation page you can put a notice at the top or bottom of a page (some examples):

: ''This article is about cream, the food item. There is another article on the [[Cream (band)|rock band Cream]].''

Or

----

'''Horse''' is also a [[slang]] term for the [[recreational drug]] [[heroin]].

'''Horse''' is also a mini-game of [[basketball]].

Or (short version at the top of the page)

:''Alternate uses: see [[California (disambiguation)]].''

There is rarely any need for links directly to disambiguation pages; in most cases links should point to the article that deals with the specific meaning intended, and not to a disambiguation page. Most times, the disambiguation page may be an orphan. Before making a page into a disambiguation page one should first look at each page that links to it (using the "pages that link here" feature of the software) and correct the links appropriately. Of course, the whole point of making a disambiguation page is so that accidental links made to it will make sense, so it's not a major problem if there are still links to it; indeed some may argue that finding unexpected things is part of what makes Wikipedia interesting (as long as you can still find the expected things as well).

The Wikipedia software has a special page that lists "orphaned" pages; that is, pages that no other page links to. For disambiguating pages, we usually want pages to link to the more specific pages, so they may be "orphaned".

"Special:Whatlinkshere/Wikipedia:Disambiguation" is a special page which lists all disambiguation pages.