| Authorization | Yes | The authorization string, which comprises MQ + space + <AccessKey ID> + : + <Signature>. For more information, see Request signatures |
| Content-Length | Yes | The length of the HTTP request body. |
| Content-Type | Yes | The Multipurpose Internet Mail Extensions (MIME) type of the request content. Currently, the request content supports only text/xml, charset=utf-8. |
| Date | Yes | The time when the request is created. Currently, only the GMT format is supported. If the difference between the creation time and the RocketMQ broker exceeds 15 minutes, the request is invalid. |
| Host | Yes | The HTTP endpoint that you found on the Instances page of the console. |
| x-mq-version | Yes | The version of the RocketMQ API. The current version is 2015-06-06. |