contentType

The "cty" (content type) Header Parameter is used by JWS applications to declare the media type (IANA.MediaTypes) of the secured content (the payload). This is intended for use by the application when more than one kind of object could be present in the JWS Payload; the application can use this value to disambiguate among the different kinds of objects that might be present. It will typically not be used by applications when the kind of object is already known. This parameter is ignored by JWS implementations; any processing of this parameter is performed by the JWS application. Use of this Header Parameter is OPTIONAL.