All event postings are viewable by all residents and so fall under Global Standards of the Community Standards. The event descriptions need to conform to PG guidelines - which include "No content depicting sex, strong violence, or anything else broadly offensive." Linden will remove events postings that don't fit the guidelines and notify the host.
We are working on a way to allow users to choose to see more mature event descriptions but until we do, all descriptions need to be PG whether or not the actual event is rated PG or M or takes places in a PG or M region.