From my perspective, that is not a use question; it's a disclosure question. If it's across two separate institutions, they would have to satisfy the disclosure requirement, so they'd first have to have an authority. The idea of also layering on top of that for any disclosure a consideration of proportionality and necessity, I think, is a very good idea and speaks to.... Those provisions tend to be discretionary provisions, so giving some guidance in terms of, even if you have the authority, what you should consider in exercising your discretion, especially sharing between government departments, would be an excellent idea.
On October 4th, 2016. See this statement in context.