Dispose(bool disposing) executes in two distinct scenarios. If disposing equals true, the method has been called directly or indirectly by a user's code. Managed and unmanaged resources can be disposed. If disposing equals false, the method has been called by the runtime from inside the finalizer and you should not reference other objects. Only unmanaged resources can be disposed.

Protected Overloads Overridable Sub Dispose( _
   ByVal disposing As Boolean _
) 

Dim instance As BaseTarget
Dim disposing As Boolean
 
instance.Dispose(disposing)

protected virtual void Dispose( 
   bool disposing
)

protected:
virtual void Dispose( 
   bool disposing
)