Clarification of Rater Group (Core, Expansion, and Expansion Plus)

[Jacobsonradical]

Hi,

Could you please help clarify what the Core, Expansion, and Expansion Plus rater groups mean? I understand these categories differ based on the countries where raters reside, but I have a couple of specific questions:

• Can we get a list of countries included in each group?
• How is a rater’s location determined? For example, if someone uses a VPN when signing up as a contributor, could that result in being classified into the wrong region?

Thank you very much for your clarification.