What approach is used in the passed entities?

Question

RESTful API

What approach is used in the case when instead of an entity object, Id is passed and why not companyId is written, but company, although id is passed

{
    entities: [
        {
            id: 101,
            name: "something1",
            company: 201,
        },
        {
            id: 102,
            name: "something2",
            company: 201,
        }
    ],
    companies: [
        {
            id: 201,
            name: "someCompany"
            owner: 301,
        }
    ],
    owners: [
        {
            id: 301,
            firstName: "Bart",
            lastName: "Simpson"
            email: "[email protected]",
        }
    ],
}

Answer 1

It's just that the author of this API decided to call it that. There doesn't seem to be a special name for it.
Although you can call it "The author is an eccentric"

Answer 2

It is unlikely that the approach has any name
There is no need to burden the response from the server with an unnecessary entity, if this entity is needed, then you can request it by identifier