I do not find any info regarding the countries table in the documentation. As most of the variables in that table seems obvious, I am not sure what is really needed for sovereignty.
Would it be possible to add a section about this table in the documentation with a country example as well as for table zones?
Not sure if this is what was being asked, but the countries table would be derived from the table in List of ISO 3166 country codes - Wikipedia, which contains a Sovereignty column. Let me know if this helps or if you need more clarification.