Certification
- Australia:MA15+
- Australia:M (some episodes)
- Canada:14A (Manitoba, DVD rating)
- Canada:R (Nova Scotia, season 1, DVD rating)
- Canada:13+ (Quebec)
- Germany:16
- Netherlands:16 (series 1, 2 and 4)
- Netherlands:12 (series 3)
- New Zealand:R16
- South Africa:16 (series 1-3, DVD rating)
- Sweden:15 (self-applied)
- United Kingdom:15
- United Kingdom:18 (series 6)
- United States:TV-MA