Remove subscribers based on subscriber ID from a tag. (Called "lists" within the GUI application).
Note:  This API call can also be found under the requesttype of "Subscribers".
JSON Request Example:
{
  "username": "JohnDoe",
  "usertoken": "anc123abc123abc123abc123",
  "requesttype": "Tags",
  "requestmethod": "UntagSubscribers",
  "details": {
    "tag": ["{*tag_id or tag_name*}", "{*tag_id or tag_name*}"], /* required: at least one */
    "subscriberid": ["{*subscriber_id*}", "{*subscriber_id*}"] /* required: at least one */
  }
}"json_request" element
| Field Name | Description | 
| username | Username used to login to Pinpointe | 
| usertoken | Unique token assigned to Pinpointe account | 
| requesttype | Tags | 
| requestmethod | UntagSubscribers | 
Please note: ALL OPTIONAL tags that are not used should be deleted from submitted call. if only one <tag></tag> and / or <subscriberid></subscriberid> element is/are being used, remove all unused elements. 
"details" element
"tag"
| Field Name | Description | 
| tag (Required) | ID of tag to be searched. At least one required. | 
| subscriberid (Required) | ID of subscriber being removed from tag. At least one required. | 
Successful Response:
"response" element
| Field Name | Description | 
| status | Will return SUCCESS if contact(s) were successfully removed from the tag(s). | 
| data | Tag count contact(s) were removed from | 
Unsuccessful Response:
"response" element
| Field Name | Description | 
| status | Will return FAILED if unsuccessful | 
| errormessage | Text explaining why request failed |