What do you understand under PG?
Never heared that..
He means this, hope it helps:
The content is mild in impact
The impact of PG (Parental Guidance) classified films and computer games should be no higher than mild, but they may contain content that children find confusing or upsetting and may require the guidance of parents, teachers or guardians. For example, they may contain classifiable elements such as language and themes that are mild in impact.
PG-rated content is not recommended for viewing by people under the age of 15 without guidance from parents, teachers or guardians.