The 16 Oatmeal Regions (12 which came online 2 weeks ago) seem to be the Linden Adult access testing regions . Some Linden has conveniently built large prim letters to show the region access rating of each Oatmeal region :
Here is an in world view (Oatmeal 15 and 12 are currently open to the public)
Every region on the Grid when queried has an access type associated with this . Until recently this field has always returned three states - "PG", "Mature" or "Down" - "Down" is a special case when that region is offline (i.e. appears Red on the Map) . Two weeks ago a new setting appeared "42" . There are currently 7 regions on the Grid with this setting - the 6 Oatmeal regions marked as A in the first image above and the Arapaima Adult Safe Hub just to the West of Ursula I mentioned a few posts ago:
Arapaima Safe Hub :
Currently the 153 Ursula regions are all marked as "Mature" and not this new "42" type which I assume is the Adult Rating
There is one Mainland openspace, Odezia, which for a long time has had yet another access type ("min"). I assume this is a database error as there also used to be a now offline linden region with the same access type. The current viewer reads this type as "Unknown" , whilst the "42" is read as "Mature", though access is barred to NPIOF who are not Age verified.