Capabilities for creating a relation to an existing entity during insert

The following request creates an Employee entity and associates it to an existing Employee entity via the Manager navigation property.

POST Employees

{
  "Manager@odata.bind": "Employees(0)",
  "Name": "Peter"
}

Is there a Capabilities annotation on the navigation property that would forbid this operation?

• UpdateRestrictions/NonUpdatableNavigationProperties controls changing a relation during update.
• InsertRestrictions/NonUpdatableNavigationProperties controls creating a relation together with the related entity during insert.
• What controls creating a relation to an existing entity during insert?