The relationship of an identifier specified in the schema is not enforced

The following statement in vnc_cfg.xsd describes that a physical-router can be created only with parent identifier "global-system-config"

<xsd:element name="physical-router" type="ifmap:IdentityType"/>
<xsd:element name="global-system-config-physical-router"/>
<!--#IFMAP-SEMANTICS-IDL
     Link('global-system-config-physical-router',
             'global-system-config', 'physical-router', ['has']) -->

However, I could create a physical-router with "domain" as parent identifier

root@nodec39:/usr/lib/python2.7/dist-packages# curl -H "Content-Type: application/json" http://localhost:8082/physical-router/2add9940-9d69-4ab6-bd00-aafca3baf7c0 | python -m json.tool
  % Total % Received % Xferd Average Speed Time Time Time Current
                                 Dload Upload Total Spent Left Speed
100 878 100 878 0 0 209k 0 --:--:-- --:--:-- --:--:-- 285k
{
    "physical-router": {
        "display_name": "prouter1",
        "fq_name": [
            "default-domain",
            "prouter1"
        ],
        "href": "http://localhost:8082/physical-router/2add9940-9d69-4ab6-bd00-aafca3baf7c0",
        "id_perms": {
            "created": "2016-03-29T18:35:54.914289",
            "creator": null,
            "description": null,
            "enable": true,
            "last_modified": "2016-03-29T18:35:54.914289",
            "permissions": {
                "group": "cloud-admin-group",
                "group_access": 7,
                "other_access": 7,
                "owner": "cloud-admin",
                "owner_access": 7
            },
            "user_visible": true,
            "uuid": {
                "uuid_lslong": 13619073275223799744,
                "uuid_mslong": 3088793422243908278
            }
        },
        "name": "prouter1",
        "parent_href": "http://localhost:8082/domain/997175e8-448d-4d18-a8fc-04b1cc70e35f",
        "parent_type": "domain",
        "parent_uuid": "997175e8-448d-4d18-a8fc-04b1cc70e35f",
        "perms2": {
            "global_access": 0,
            "owner": null,
            "owner_access": 7,
            "share": []
        },
        "uuid": "2add9940-9d69-4ab6-bd00-aafca3baf7c0"
    }
}