You can add checklists to a task for tracking purposes.
To get a checklist:
GET api/enterprise/tasks/{taskId}/checklist
    To create a checklist:
POST api/enterprise/tasks/{taskId}/checklist
Example request body:
{
    "assignee": {"id": 1001},
    "name": "mySubtask",
    "parentTaskId": "20086"
}
    To change the order of the items on a checklist:
PUT api/enterprise/tasks/{taskId}/checklist
    with a json body that contains an ordered list of checklist items ids:
- 
order : Array of checklist item ids