An idea I had but never really executed on was a mechanism for tagging documentation as "should be reviewed at least once every X months" - for things like setting up developer environments.

That way a team could be alerted if their documentation was due-for-review. One person gets assigned a task to review it. They look through it, update it if necessary, and either way put a "last reviewed by X on date Y" tag on it so people who read it can tell that it's still relevant.