A canonical form thus provides a classification theorem and more, in that it not just classifies every class, but gives a distinguished (canonical) representative.
When a couple has received a dispensation, the partners may validate the marriage by a simple renewal of consent according to canonical form as a new act of the will.
On an arbitrary almost complex manifold one can always find coordinates for which the almost complex structure takes the above canonical form at any given point "p".
Formal equivalence relations among the sentences of a coherent discourse are made explicit by using sentence transformations to put the text in a canonical form.