The action came nearly two years after the IAU introduced the category of dwarf planets, demoting Pluto from being categorized as a planet.
The IAU, headquartered in Paris, defines plutoids as being celestial bodies in orbit around the sun at a distance greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (nearly-spherical) shape, and that have not cleared the neighborhood around their orbit.
The two known and named plutoids are Pluto and Eris. It is expected that more plutoids will be named as new discoveries are made.
The IAU has been responsible for naming planetary bodies and their satellites since the early 1900s.