This must be an error
Just as proteins have a polarity defined by the amino and carboxyl termini, oligosaccharides have a polarity defined by their reducing and nonreducing ends. The carbohydrate unit at the reducing end has a free anomeric carbon atom that has reducing activity because it can form the open-chain form, as discussed earlier (p. 325). By convention, this end of the oligosaccharide is still called the nonreducing end even when it is bound to another molecule such as a protein and thus no longer has reducing properties.
In my opinion, this sentence only makes sense if it would read reducing. Can anyone confirm?