I received a DWG file that had an attached PRJ file. This is what the PRJ says;
PROJCS["NAD_1983_2011_StatePlane_Illinois_West_FIPS_1202_Ft_US",GEOGCS["GCS_NAD_1983_2011",
DATUM["D_NAD_1983_2011",SPHEROID["GRS_1980",6378137.0,298.257222101]],
PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],
PARAMETER["False_Easting",2296583.333333333],PARAMETER["False_Northing",0.0],
PARAMETER["Central_Meridian",-90.16666666666667],PARAMETER["Scale_Factor",0.9999411764705882],
PARAMETER["Latitude_Of_Origin",36.66666666666666],UNIT["Foot_US",0.3048006096012192],AUTHORITY["ESRI",103038]]
My question is, at the end of the string it says - AUTHORITY["ESRI",103038], what does this mean?