CG-70: Children's Guidance Suggested with Parents/People Over 70
A performance or social event which may be unsuitable for people over the age of 70, due to generational changes into what is considered acceptable and decent. The "CG-70" rating is slightly more relaxed than the stricter "CG" rating, which is a warning that children should exercise caution if parents of any age (including those younger than 70) are expected to be present.
Bride: Love, our parents are inviting all their friends to our wedding, and, sure enough, since there's four of them and only two of us, and since they've accumulated many more friends in the extra decades they have on us, it looks like the average age of the wedding is going to be bumped up well into the 60's.
Groom: Shit. I better tell the best man to expect a CG-70 event and tailor his speech accordingly so he doesn't offend hundreds of old farts.