I think you're asking an important question. Within the CRA we're clear on certain policies and practices in terms of how many tax years we go back. For ordinary salaried Canadians, we focus on the current tax year. We find a mistake. We don't go back to the maximum limit. We just take a perspective approach and say, “Don't make that mistake again.”
With businesses and high net-worth individuals, we tend to stay in the two- to four-year range. Again, it's educational; let's correct it and let's move on. When you get into aggressive tax planning, we start to move to a six-year review. We sought legislative changes to get nine years. In exceptional cases we can justify going to 16 years. The CRA tries to adjust its approach, but that's an internal policy. We haven't had that up on the website where we could point to that to explain to taxpayers what we normally do and in which exceptional cases we would we go further.