Under Moderators' Guidelines for actionable posts:
The "PG13" standard is loosely used as a guideline to what is/isn't acceptable when determining whether a comment is vulgar. If society has deemed it appropriate for a 13 year old to hear, it is unlikely that it will be offensive to the majority of Users. It should be noted that PG13 does include some use of the “f” word. We understand that this is ambiguous so please report any posts that you feel cross the line.