message: Introduce a general way to mark entity references
diff: @@ -447,11 +447,16 @@ group of people in an organizational structure.
  ### `spec.system` [optional]
  -Links the system that the component belongs to, e.g. `artist-engagement-portal`.
  -This field is optional.
  +An [entity reference](#string-references) that to the system that the component
  +belongs to, e.g. `artist-engagement-portal`. This field is optional.
  -The software catalog expects a single string that references the name of an
  -entity of the `kind` `System`.
  +| Default [`kind`](#apiversion-and-kind-required) | Default [`namespace`](#namespace-optional) | Generated [relation](well-known-relations.md) type |
  +| ----------------------------------------------- | ------------------------------------------ | ----------------------------------------------------------------------------- |
  +| [`System`](#kind-system) (only) | Same as this entity, typically `default` | [`partOf`, and reverse `hasPart`](well-known-relations.md#partof-and-haspart) |
  +
  +| [`kind`](#apiversion-and-kind-required) | Default [`namespace`](#namespace-optional) | Generated [relation](well-known-relations.md) type |
  +| --------------------------------------------------------- | ------------------------------------------ | ----------------------------------------------------------------------------- |
  +| [`System`](#kind-system) (default), [`API`](#kind-system) | Same as this entity, typically `default` | [`partOf`, and reverse `hasPart`](well-known-relations.md#partof-and-haspart) |
  ### `spec.providesApis` [optional]
  