Cascaded Hold in order Lines and Included Items

Hi Friends,

Can you please help me in understanding of

 

1. cascaded hold flag in order lines screen?

 

2. "Hold Included Items" Check Box in the Hold Setup Screen.

As per Order Management Implementation manual,

In Define Hold Screen in Order Management,
Optionally, select the 'Hold Included Items' check box. Hold included items allow the user to cascade the hold placed against a model to the 'included items' defined in the model.

But,applying hold on the top level PTO Model cascades hold on included items(all BOM Components) even when the "Hold Included Items" check box is unchecked.

3. What is exactly meant by "Included Items" and "Model" being described here?