Nomenclature of The Galactic Center Radio Sources
  Since its identification as the Galactic Center, the radio source Sagittarius A has been a target of intense research. Due to the high density of sources in the Galactic Center and differing observing techniques, the nomenclature of sources in this region has changed over the years, with sources having several names, as well as the same names being used for different sources. We review this historical evolution in the context of current and previous scientific discussions, and outline how, why and when some of the commonly accepted names of Galactic Center sources were established. 
Patrick Palmer and W. Miller Goss