Rating systems

Here are some interesting rating systems. Do you know what they are?

System 1 (online)

 * B: 1-4. There is no violence, language, sex, adult themes, or ideas children under 5 cannot comprehend. This rating is not used by fanfiction.net, but it is available.
 * K: 5+. No violence, language, sex, or adult themes.
 * K+: 9+. No sex or adult themes. Contains some violence/language,
 * T: 13+. Some non-suggestive adult themes, violence, and language.
 * M: 16+. Adult themes, violence, and language.
 * MA: 18+. Graphic violence, strong language, and explicit sexual content. This rating isn't used by fanfiction.net (it is available though).

System 2

 * A-I: all ages
 * A-II: 13 and up
 * A-III: 18 and up
 * L: limited adult audience; not suitable for most adults.
 * O: morally offensive; totally prohibited from viewing by any age.