…from the ESRI Map Book, Volume 24…
“The example map shows the coordinate shifts for National Geodetic Survey control stations in Maricopa County, Arizona (the Phoenix metro area is in the central portion of the state), resulting from the national readjustment completed in February 2007. The coordinates being compared are for two realizations of North American Datum of 1983 (NAD83); NAD83 (1992) also known as the High Accuracy Reference Network (HARN) realization; and NAD83 (NSRS2007), also denoted as NAD83 (2007), for example on NGS datasheets. “NSRS” stands for National Spatial Reference System.
“The issue being addressed here is of interest for those who have data layers with positional accuracies of a few centimeters with respect to NAD83 (HARN) and who wish to preserve the accuracy of those layers in the future.
“Courtesy of the Arizona State Land Department.”