In 11. OpenAPI 3.0 Requirements Class, it is required that both an OpenAPI 3.0 and an HTML API definition be provided, however the requirement does not explicitly state that the link to the OpenAPI should be using service-desc while the HTML one should be using service-doc (the Abstract Test 24 however explicitly checks that).
In 11. OpenAPI 3.0 Requirements Class, it is required that both an OpenAPI 3.0 and an HTML API definition be provided, however the requirement does not explicitly state that the link to the OpenAPI should be using service-desc while the HTML one should be using service-doc (the Abstract Test 24 however explicitly checks that).
In OGC API - Features, this is explicitly described in requirement 46.