A particular use of a stepwise constant is in the determination of stability constant values outside the normal range for a given method. For example, EDTA complexes of many metals are outside the range for the potentiometric method. The stability constants for those complexes were determined by competition with a weaker ligand.
:ML + L′  ML′ + L  
The formation constant of [[Palladium(II) cyanide|[Pd(CN)]]] was determined by the competition method.