To Lock or Unlock an Instance
You can lock an instance of a Family Table so that you cannot modify the table-driven characteristics of the instance. If a feature is deleted, the family table instance automatically changes from Y to N, even though the instance is locked in the family table. Under Type a lock appears in the locked instance row.
1. Click Tools > Family Table. The Family Table dialog box opens.
2. Select the names of the instances that you want to lock. Press and hold CTRL to select more than one instance.
3. Click Tools > Lock / Unlock Instance, or click . A lock icon appears next to each instance name.
The instances are locked when you click OK to save the table or click Open to open the instance.