Missing `region` and `country` data on some `division_area` polygons

Discussed in https://github.com/orgs/OvertureMaps/discussions/353

^{Originally posted by rmvegasm March 19, 2025}
Hi, I've noticed some missing data on the region ISO-3166-2 codes for some units. Some are places with partial diplomatic recognition or other political issues that might explain the situation, e.g. Kosovo (ISO-3166-1:XK) that is still listed as an autonomous region of Serbia within the standard. Others, however, should have all the info available in the ISO-3166, like for instance 'El Salvador'. I've also noticed two county-level divisions with no country code either.

For me, and I assume for others as well, the primary issue with this is the inability to query administrative units below the municipality level without having to resort to spatial operations.

Here's a list of country codes for which there's no region data:

"MG" "MM" "XW" "NA" "GG" "SO" "XP" "XR" "LB" "MA" "NC" "AS" "JE" "TL" "RS"
"XG" "GM" "EG"  "XK" "KG" "IN" "GF" "AG" "AX" "PH" "TH" "AO" "CC" "NR"
"ST" "PF" "DZ" "XU" "SV" "SS" "GS"

And the name.primary field for those missing also a country entry:

Mukah Division - Beting Patinggi Ali Shoals (disputed)
中沙群岛的岛礁及其海域                                

Hope this helps improving this amazing dataset, infinite thanks for making this available!