If a radius search has an ambiguous origin, and ambiguities is not set to Ignore, the response from Mapquest consists of a Collections element, containing the various possibilities for the origin, rather than the search results.
Is there documentation somewhere of this Collections element? In JSON, it appears to be an array with one element, which is also an array (of locations). Does the outer array ever have more than one element, and if so, what is it? Or can we always expect an array of array of locations?