This is an administrative category, used for maintenance of the Wikipedia project. It is not part of the encyclopedia and contains non-article pages, or groups articles by status rather than subject. Do not include this category in content categories (except for eponymous maintenance categories).

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This category is triggered by the language infobox if 'speakers' is set to "?" and there is no ref field. (If there is an entry in the ref field, the number of speakers is presumably actually unknown, rather than our article simply lacking a source.)