To add, I will give you a sense of the reason why a province or territory might use that information. You could have a family with children just coming on social assistance. They might be eligible for certain transition payments. Let's say they've experienced a drop in income. It will be a while before the Canada child benefit catches up to that, because it's based on the prior year's income. Certain provinces have a system of bridging some of that until their Canada child benefit goes up.
Basically, they're using the information on eligible children. They'll have some information on the last year's income—basic information on the family.
That would be an example of how it's used.