One of the most recent changes came about because of the Federal Accountability Act, which added a section in the Access to Information Act. I believe it's the Information Commissioner or Treasury Board that then notifies the departments that these changes have been made. It's then up to the delegated authority—and also the analysts working on the file—to make sure they're aware that these sections are there and what it might mean to you when you're reviewing a file.
I believe that's the process.