It should say 'Fe'. 'Fe' as found in 'fe'rrous. Ferrous things contain iron because the metal 'iron' is represented by the symbol Fe. Something non-ferrous is devoid of iron. Thus, a non-ferrous metal is a metal (or a mixture of two or more metals) that contains inconsequential amounts or no amount of iron. They are therefore nonmagnetic and don't rust like ferrous metals do.