Certification
- Australia:M
- Brazil:14 (season 1)
- Brazil:16 (season 2)
- Canada:PG (Manitoba/Ontario, DVD rating)
- Canada:14A (Nova Scotia, DVD rating)
- Canada:G (Quebec)
- France:Tous publics
- Germany:12
- Ireland:15 (most episodes)
- Ireland:12 (some episodes)
- Italy:T
- Mexico:PG-13 (DVD rating)
- Netherlands:6
- Netherlands:12 (seasons 3 and 4)
- New Zealand:M
- Poland:15 (DVD rating)
- Russia:16+
- Sweden:16+ (self-applied)
- United Kingdom:15
- United Kingdom:12 (most episodes)
- United Kingdom:15 (season 3 DVD)
- United States:TV-14