Enclaves

Global

A region entirely surrounded by another region's territory (e.g. Lesotho in South Africa) can be mis-assigned to the surrounding region by centroid- or overlap-based admin joins.

Detection

Region polygon is fully contained within another region's polygon (within() true, not just intersects).

Mitigation

Use polygon-in-polygon precedence rules, inner region wins on containment
Maintain an explicit enclave/exclave exceptions list for known cases

Affected conversions

Admin polygonsH3 (max-overlap partition)
Admin polygonsH3 (weighted crosswalk)
H3platform-native IDs