I think I support that suggestion but that is unclear to me how a conformance class is represented.

Is that implementation-oriented, like some code examples, or specifications-oriented with every criteria phrased ? Do you have any example from another specification document ?

@balessan eg. https://www.w3.org/TR/ldn/#conformance-classes states:

LDN implementations may be senders, receivers or consumers. The conformance criteria for each of these roles are described in their respective sections of this specification.

and that can of course be expressed/structured in different ways.

As for the machine-readable parts, see eg. block starting at view-source:https://www.w3.org/TR/ldn/#line343 (in Firefox) - essentially each conformance class links to its own specific requirement that can be tested. The human-readable version should communicate that.

https://www.w3.org/TR/ldn/#exit-criteria describes implementation:

An implementation is an LDN sender, receiver or consumer which implements the corresponding conformance class of the specification.