# Common Request Parameters

Table 1 describes the common request parameters.

Table 1 Common request headers
Parameter | Mandatory | Description
--- | --- | ---
X-Sdk-Date | This parameter is mandatory for authentication using AK/SK. | Time when the request is sent. The time is in the YYYYMMDD'T'HHMMSS'Z' format. The value is the current GMT time of the system.
Authorization | This parameter is mandatory for authentication using AK/SK. | Signature authentication information. The value can be obtained from the request signing result. See Authentication.
Host | This parameter is mandatory for authentication using AK/SK. | Server domain name and port number of the resource being requested. The value can be obtained from the URL of the service API. The value is hostname[:port]. If the port number is not specified, the default port is used. The default port number for https is 443.
Content-Type | Yes | MIME type of the request body.
Content-Length | This parameter is mandatory for POST and PUT requests, but must be left blank for GET requests. | Length of the request body. The unit is byte.
X-Project-Id | No | Project ID. This parameter is used to obtain the token for each project.
X-Auth-Token | No (This parameter is mandatory for authentication using tokens.) | User token.
X-Language | No | Request language. The value is en-us.
Accept | No | Type of content that can be received by a client.

Parent topic: Common Parameters