Investigation of USNO-A2.0 Catalog positions

We present an investigation of the USNO-A2.0 Catalog positions. We have com pared USNO-A2.0 positions with the Astrographic Catalogue-Tycho, with impro ved HST Guide Star Catalog positions in the ACT frame, and with Internation al Celestial Reference Frame source positions and observational data from V alinhos CCD Meridian Circle, covering all the USNO-A2.0 magnitude range wit hin 7 less than or equal to V less than or equal to 22. We report striking, peculiar features first found for the USNO-A2.0 catalog positions, which a re different for its northern and southern parts.