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The International Astronomical Union invented the designation ""dwarf planet"" in 2006. Prior to that time it did not exist, and it has no meaning other than whatever meaning the IAU is pleased to confer upon it. When Wikipedia uses the term ""dwarf planet"", it means whatever the IAU means by ""dwarf planet"", regardless of what any other person may use the term to mean. The statement that there are ""hundreds or thousands of dwarf planets"" is not accurate; there may be hundreds of candidate objects, some of which might some day be accepted as dwarf planets, and there may be thousands of objects yet to be discovered which might be candidates for being labelled dwarf planets, but at this moment, there are only five objects which actually are dwarf planets. Because ""dwarf planet"" is an arbitrary label, we cannot reasonably say that, say, Sedna or Quaoar are dwarf planets; they would only become dwarf planets at such future date as they may be named as such, which depends upon obtaining accurate data as to their size, mass, composition, and shape, which is not as yet available. To say definitively that there are dwarf planets other than the five that have been named goes far beyond what Wikipedia is entitled to do. At most the project can say that certain objects, at some future date, might be designated as dwarf planets.  "