Under the current regime, from a pure copyright perspective, there's no real difference between the crown and Margaret Atwood. It's the same. The amount that someone may use of those documents is going to depend on whether they qualify under the fair dealing exception. Fair dealing isn't a bright-line test. It's hard for me to tell you that you can use this and not that. It depends on circumstances and the like, but if you don't qualify for fair dealing, you have to ask for permission.
On December 9th, 2010. See this statement in context.