Redmine

It would be great if Redmine allows for creating new Tracker only when it is a Subtask (ideally when this Subtask's Parent is a particular Tracker).
This would allow for creating Tracker's hierarchy: for example - I have a Tracker "Activity", which consist of several steps that have to be done in order to complete "Activity". Let's call them "Step 1" and "Step 2". Then "Step 1" and "Step 2" cannot be created as top-level task (Tracker) and cannot be assigned to Top-level tracker other than "Activity". We obtain:

• Issue Tracker: "Activity"; Status: "New"; Subject: "Some important activity"
  • Issue Tracker: "Step 1"; Status: "In Progress"; Subject: "Very important step"
  • Issue Tracker: "Step 1"; Status: "New"; Subject: "Another important step"

Kind regards