Specifies whether a leaf system is active and applicable for modeling, drawing, and
reporting operations. To exclude the leaf system from these operations, select No. In the hierarchy explorer, the lock icon 
is shown over the icon of the deactivated leaf system, and the detailed or light
part associated with the leaf system is also deleted. In addition, because connections
to deactivated leaf system are not valid, you must resolve such invalid connections
in the To Do List. To change the leaf profile system back to the active state, select Yes; however, to have the detailed part, you must detail the leaf system explicitly.
See Marine Structure Hierarchy in the Workspace Explorer for more information on leaf systems.