A file resource can represent all kinds of files like shipment labels, available in different file formats.
If you request a file using the default Accept header application/vnd.api+json, you will get a list of the supported formats of that file. This list can contain the following mime types:
Retrieve A File In A Specific Format
Use these mime types as Accept header to retrieve the actual file as binary data.
The response will be of the same mime type and contain the raw file data.