Under the act there is no definition of private interest, but we do have what is not considered to be of private interest. That's found in the definitions section:
private interest does not include an interest in a decision or matter (a) that is of general application; (b) that affects a public office holder as one of a broad class
We have that identical provision in the code. However, in the code we have what is considered a private interest, and it's mostly a pecuniary interest. We don't have the definition in the act that we have in the code.