When I create a sub-interface:

PUT http://10.0.0.5:8181/restconf/config/ietf-interfaces:interfaces
{
"interfaces": {
"interface": [
{
"name": "GigabitEthernet0/9/0",
"type": "iana-if-type:ethernetCsmacd",
"enabled": "false",
"vpp-vlan:sub-interfaces": {
"sub-interface": [
{
"identifier": "1",
"vlan-type": "802dot1q",
"tags": {
"tag": [
{
"index": "0",
"dot1q-tag":

Unknown macro: { "tag-type"}

},
{
"index": "1",
"dot1q-tag":

Unknown macro: { "tag-type"}

}
]
},
"match": {
"vlan-tagged":

Unknown macro: { "match-exact-tags"}

},
"enabled": "false"
}
]
},
"v3po:ethernet":

Unknown macro: { "mtu"}

},
]
}
}

I get the list of interfaces (operational data):

curl -v -su admin:admin http://10.0.0.5:8181/restconf/operational/ietf-interfaces:interfaces-state?prettyPrint=true;echo

• Trying 10.0.0.5...
• Connected to 10.0.0.5 (10.0.0.5) port 8181 (#0)
• Server auth using Basic with user 'admin'
  > GET /restconf/operational/ietf-interfaces:interfaces-state?prettyPrint=true HTTP/1.1
  > Host: 10.0.0.5:8181
  > Authorization: Basic YWRtaW46YWRtaW4=
  > User-Agent: curl/7.42.1
  > Accept: /
  >
  < HTTP/1.1 200 OK
  < Set-Cookie: JSESSIONID=1x6mr1nn03x4z7ph4aui363i5;Path=/restconf
  < Expires: Thu, 01 Jan 1970 00:00:00 GMT
  < Set-Cookie: rememberMe=deleteMe; Path=/restconf; Max-Age=0; Expires=Tue, 14-Jun-2016 11:44:19 GMT
  < Content-Type: application/yang.data+json
  < Vary: Accept-Encoding, User-Agent
  < Transfer-Encoding: chunked
  < Server: Jetty(8.1.15.v20140411)
  <
  {
  "interfaces-state": {
  "interface": [
  {
  "name": "GigabitEthernet0/9/0",
  "vpp-vlan:sub-interfaces": {},
  "v3po:ethernet":
  Unknown macro: { "mtu"}

  ,
  "speed": 1000000000,
  "admin-status": "down",
  "if-index": 7,
  "phys-address": "08:00:27:5b:b6:e0",
  "type": "iana-if-type:ethernetCsmacd",
  "oper-status": "down"
  },
  {
  "name": "GigabitEthernet0/8/0.1",
  "vpp-vlan:sub-interfaces": {},
  "v3po:ethernet":

  Unknown macro: { "mtu"}

  ,
  "speed": 1000000000,
  "admin-status": "down",
  "if-index": 8,
  "type": "iana-if-type:ethernetCsmacd",
  "oper-status": "down"
  },
  {
  "name": "GigabitEthernet0/8/0",
  "vpp-vlan:sub-interfaces": {
  "sub-interface": [
  {
  "identifier": 1,
  "tags": {
  "tag": [
  

  Unknown macro: { "index"}

  ,

  Unknown macro: { "index"}

  ]
  },
  "oper-status": "down",
  "match":

  Unknown macro: { "vlan-tagged"}

  ,
  "if-index": 8,
  "speed": 1000000000,
  "admin-status": "down"
  }
  ]
  },
  "v3po:ethernet":

  Unknown macro: { "mtu"}

  ,
  "speed": 1000000000,
  "admin-status": "down",
  "if-index": 6,
  "phys-address": "08:00:27:92:bb:26",
  "type": "iana-if-type:ethernetCsmacd",
  "oper-status": "down"
  },
  {
  "name": "local0",
  "vpp-vlan:sub-interfaces": {},
  "type": "iana-if-type:ethernetCsmacd",
  "admin-status": "down",
  "if-index": 1,
  "oper-status": "down"
  },
  {
  "name": "pg/stream-2",
  "vpp-vlan:sub-interfaces": {},
  "type": "iana-if-type:ethernetCsmacd",
  "admin-status": "down",
  "if-index": 4,
  "oper-status": "down"
  },
  {
  "name": "pg/stream-3",
  "vpp-vlan:sub-interfaces": {},
  "type": "iana-if-type:ethernetCsmacd",
  "admin-status": "down",
  "if-index": 5,
  "oper-status": "down"
  },
  {
  "name": "pg/stream-0",
  "vpp-vlan:sub-interfaces": {},
  "type": "iana-if-type:ethernetCsmacd",
  "admin-status": "down",
  "if-index": 2,
  "oper-status": "down"
  },
  {
  "name": "pg/stream-1",
  "vpp-vlan:sub-interfaces": {},
  "type": "iana-if-type:ethernetCsmacd",
  "admin-status": "down",
  "if-index": 3,
  "oper-status": "down"
  }
  ]
  }

• Connection #0 to host 10.0.0.5 left intact
  }

The interface "GigabitEthernet0/8/0.1" (the second in the list) must not be there.