Wikipedia:Scope

The scope of an article is the range of material that belongs in the article, and thus also determines what does not belong in it (i.e., what is "out of scope").

The title together with the lead section (ideally, the introductory sentence or at least the introductory paragraph) of an article should make clear what the scope of the article is.

All material that is notable, referenced and that a reader would be likely to agree matches the specified scope must be covered (at least in a summarize fashion).

What reliable sources say about material that is out of scope for the decided-upon subject is largely irrelevant to that article and can be removed or moved to another article.

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Wikipedia