# PostBody Object * `data` ([UploadRawData](upload-raw-data.md) | [UploadFile](upload-file.md))[] - The post data to be sent to the new window. * `contentType` string - The `content-type` header used for the data. One of `application/x-www-form-urlencoded` or `multipart/form-data`. Corresponds to the `enctype` attribute of the submitted HTML form. * `boundary` string (optional) - The boundary used to separate multiple parts of the message. Only valid when `contentType` is `multipart/form-data`.