Case 2 is not implemented nor will it be according to https://docs.google.com/spreadsheet/ccc?key=0Aj_S9VF3rt5DdEhqZHlBaGVURmhZRDY3aDRBdlpHS3c#gid=0.

Case 3 also presents the same erroneous JSON response. I wasn't able to delete an attribute value using this URL
```
curl localhost:1026/NGSI10/contextEntities/Room1/attributes/temperature/ID -s -S --header 'Content-Type: application/json' --header 'Accept: application/json' -X DELETE
```
This is what I got:
```json
"statusCode" : {
  "code" : "472",
  "reasonPhrase" : "request parameter is invalid/not allowed",
  "details" : "action: DELETE - entity: (Room1, Room) - offending attribute: temperature"
}
```
So maybe I wasn't using it correctly?
There is a another case:
- DELETE /ngsi10/contextEntities/{EntityID}/attributes/{attributeName}
This does work, but the response message is invalid JSON as well.