Wikipedia:Ambiguous subjects

An article is meant to cover a single topic with specific subject matter. However, there are instances where the same name can refer to multiple different subjects, and those different subjects should be covered as different articles. There are also instances where a single subject is referred to by several different names, which should still be covered as a single article. Avoid conflating an article's topic with its name; be careful that you haven't lost track of a subject due to inconsistent terminology.

Deciding the scope of an article's subject matter is guided by several Wikipedia guidelines and policies. The Disambiguation guideline tells us best practices for a search term that refers to multiple subjects or topics. The Notability guideline tells us that some topics are not appropriate for a stand-alone article, but might be appropriate for a redirect or merge to another article. The Article titles policy tells us how to title those articles in a way that the subject's name is recognizable, natural, precise, concise, and consistent. Finally, the Verifiability policy tells us that all information should be grounded in references to reliable and independent secondary sources, including the heading for the subject itself.

Multiple subjects with the same name
A single word or phrase might refer to different subjects. The Disambiguation guideline says that the best solution is to cover those subjects with different articles, splitting an existing article if necessary, and to steer readers to an appropriate article using tools such as redirects, hat notes, and disambiguation pages. Even in cases where the names of the subjects are related, it is best to cover them as separate subjects when they each have separate significant coverage, in accordance with the general notability guideline.

The disambiguation guideline uses the example of Mercury (element), Mercury (planet) and Mercury (mythology). Even though all three topics are named after the Roman god, they are clearly different subjects, with their own significant coverage in reliable sources. The relationship between their names can be described in each separate article, usually an etymology section.

Single subjects with multiple names
There are many subjects that are referred to using multiple names, whether their nickname, their name in another language, or an official name change. The policy on Article titles tells us that we should strive to use a common name for the subject, which isn't always the official name, or even the most common name.

The policy on article titles gives the example of the Great Pyramid of Giza. This is the preferred article title, because it is more common than its official name, the Pyramid of Khufu, but not so common as to be ambiguous such as The Pyramids. A good article title tries to identify the subject in a way that is recognizable, natural, precise, concise, and consistent. Reliable sources will help identify alternative names that should redirect to the primary subject, or if there is no clear primary subject, a disambiguation page.

Articles about multiple subjects
When an article appears to be talking about multiple subjects, this is a sign that the topic area is not organized into specific articles. To determine the best way to organize those subjects, refer to reliable sources to determine if they have separate significant coverage, which would justify splitting those subjects into their own separate articles. If the sources reveal that there are two separate subjects, it may become clear that one or both subjects may be further organized, perhaps by renaming it to a clearer title, or even combining it with another article that is largely about the same subject.