Metadata isDefault attribute on an IndexedEndpoint

Title: Metadata isDefault attribute on an IndexedEndpoint

Can someone please confirm my understanding wrt to isDefault. 

This setting is meant to be applied for the entire set of indexed endpoints for a service. Specifically, this is so that if an internal request for an indexed endpoint

(a) does not contain an index, the "default" (as defined in the metadata spec) will be used

(b) contains an index that does not exist in the metadata, the "default" (as defined in the metadata spec) will be used

Thanks, Tom.