[SneakySnake]

I found this on the internet.. It seems to mean that swearing is OK because the U13s would be supervised!

Spoiler:

Rating Description UK equiv.
G Suitable for any age.

PG Suitable for any age but younger children may need guidance. A story at PM would only achieve this rating if it was a general Star Trek story with no sexual content whatever. No swearing and very little violence except that which you would expect to see on the television show.

PG13 Suitable for those aged 13 or over but parental guidance still required for those under 13. On this site that means mild sexual content is allowed. Likewise for language and violence. These stories may include actual or implied sexual relationships between women and between men. If such things are illegal where you live then the stories will be unsuitable for you regardless of age. 12

R These are more restricted and basically are not suitable for children under sixteen. Stories may contain sex, strong language and moderate levels of violence. On this site, to be on the safe side, R rated stories are marked as for over eighteens only together with the NC17 stories. If you are not sure that your parents would like you reading such material then don't. 15
NC17 Not suitable for those under the age of eighteen. Stories may contain explicit sex, strong language and/or violence. Stories on this site will not contain descriptions of excessive violence or non-consensual sexual violence. Any BDSM should be consensual, mild and preferably humourous. 18