[Here's the answer](http://lists.geojson.org/pipermail/geojson-geojson.org/2013-November/000863.html)

tl;dr: There is no "right" way. If it passes [geojsonlint](http://geojsonlint.com/) it's valid GeoJSON, and that's just confirming JSON structure, not that the interior rings are actually inside of the exterior ring or how to interpret what the interior rings *are*, or anything of that nature.

Personally, I'd prefer we treat it as exclusions, since the "exterior" ring doesn't have to be totally encompassing the whole area, especially since I can see some exceptions to the rule that this would allow (willing to discuss this 1:1 with you and Jed so you know what I mean, but don't want to put it in a public repo).