[OData-CSDL, example 64] annotating a navigation property or its addressed resource?

OData-CSDL contains

Example 64: model path addressing an annotation on a navigation property

…/Items@Capabilities.InsertRestrictions/Insertable

which claims to be

addressing annotations on the navigation property itself

But according to the capabilities vocabulary, this annotation applies only to entity sets and collections, not to navigation properties.

However, external annotation targets that start with a container make no distinction between a navigation property and the resource addressed by it. Is the distinction between

…/Items@Capabilities.InsertRestrictions/Insertable

and

…/Items/@Capabilities.InsertRestrictions/Insertable

perhaps entirely artificial?