852 1st Indicator 3 - Superintendent of Documents classification:

Value 3 indicates that the item is shelved by a Superintendent of Documents classification number. This number, is contained in subfield $h (Classification part), is assigned from the Superintendent of Documents Classification System. Superintendent of Documents classification numbers are assigned only by the U.S. Government Printing Office (GPO). A fuller description of the GPO classification number is given under field 086 (Government Document Classification Number).