| Full Fuzzer Name | InsertWhitespacesInFieldNamesFieldFuzzer |
| Log Key | N/A; the fuzzer name and mutation scenario identify the test. |
| Description | Inserts random Unicode whitespace characters into request field names. |
| Enabled by default? | Yes. |
| Target field types | JSON request body fields. |
| Expected result | 4XX, because the mutated field name should not be accepted as the documented field. |
| Fuzzing logic | Iterates over request fields, inserts two random Unicode whitespace characters into each field name, and sends the mutated payload. |
| Conditions when this fuzzer will be skipped | When the request payload is empty or a candidate field is not present in the JSON body. |
| HTTP methods that will be skipped | HEAD, GET, DELETE. |
| Reporting | Reports a rejected field-name mutation as the expected result; unexpected response codes and server errors follow normal CATS reporting. |