Certification
- Australia:PG
- Australia:M (DVD rating, seasons 1-4)
- Australia:MA15+ (DVD rating, seasons 5-12)
- Canada:PG (Manitoba, DVD rating)
- Germany:12
- Netherlands:6 (season 1)
- Netherlands:AL (seasons 2-10)
- New Zealand:M
- Norway:A (TV rating)
- Sweden:12 (self-applied)
- United Kingdom:PG (some episodes)
- United Kingdom:12 (some episodes)
- United States:TV-14