Parental Rating / Certification list order

[TheDreadPirate]

The parental rating should be pulled from your metadata provider for the region you are in, set in Dashboard > Libraries (and in the Metadata sub-menu). If a rating for your region doesn't exist on that metadata provider it will pull another regions rating.

If you are uniformly getting parental ratings for an entirely different region, ensure your region is set correctly in the menu I mentioned above. Or in each library's settings.

AFAIK, there is no remapping. But each rating corresponds to an age number. So if you want to set a user's max rating to PG-13, selecting any rating with an equivalent age rating of "13" would achieve the same effect.