https://tools.ietf.org/html/rfc6903#section-6 defines the "type" link relation type to indicate that a resource is an instance of a certain class of resources.

Having a link hint with the same semantics would be helpful e.g. for crawlers that are in search of certain types of resources. It would be very helpful for landing page resources that typically contain links to a range of resources with different content types. For example, in scholarship, such pages link to a scientific paper, a dataset, software, auxiliary materials, etc. The proposed link hint could meaningfully distinguish between these. Currently, only MIME type is available as a distinguishing factor.

schema.org has meanwhile minted widely used URIs to indicate many types of creative works. These could be used with a link hint to express resource class to yield powerful interoperability.