NFL information resources

I found some interesting information on NFL.com that I hadn't used before. League rules and history (1991-2000) (there are other year groups but this was what I was looking for).

I was originally just trying to figure out when the kickoff had been moved from the 35 yard line back to the 30. The answer? 1994. That explained why Jason Hanson touchback numbers plummeted after the '93 season even though his average per kick didn't change.