1.1 The Unified Numbering System (UNS) is the accepted alloydesignation system in North America for wrought and cast copper andcopper alloy products. The designation system is an orderly methodof defining and identifying coppers and copper alloys; it is not aspecification.

1.2 New designations are assigned as new coppers and copperalloys come into commercial use, and designations are discontinuedwhen an alloy composition ceases to be used commercially. Anyonemay request changes in the list.

1.3 New designations are assigned if a copper or copper alloymeets three criteria:
The complete chemical composition is disclosed
The copper or copper alloy is in commercial use or is proposed forcommercial use.
The composition does not fall within the limits of any designatedcomposition already in the list.