+Every operation will receive a response which `json` content is as follows:
+
+```json
+{
+ "result":"true",
+ "response":"<test id>"
+}
+```
+
+or
+
+```json
+{
+ "result":"false",
+ "response":"<error hint>"
+}
+```
+
+In case of success operation, the value of the affected test identifier carried in `response` field is useful when zero value was provided to automatically reserve the next test case. In case of error, a brief error description will be carried in that field.