In addition to Antarctica, 30 countries in the canonical country dataset, including Iran, Russia, and the Czech Republic, have "Antarctica" as their form_990_region (list: P55446). This is obviously wrong and should be fixed based on the official IRS region definitions (unless we have a different internal practice).

The only other obvious error I spotted was that Oman has "Europe".

If this field is likely to be used, it also be good to fix the null values since many of them are explicitly classified by the IRS or could be easily assigned following the IRS's advice to designate appropriate regions for countries not explicitly classified. For example:

• Northern Mariana Islands (explicitly "United States")
• Marshall Islands (explicitly "East Asia and the Pacific")
• Cyprus (should probably be "Middle East and North Africa", following the example of Malta)