Rear Shock Removal Question

[Jinx]

According to the Haynes manual, it states in step #3 to "Remove the nut, washer and upper insulator. Discard the nut."

Why discard the nut? Is it absolutly necessary to throw it away? Why can't you just reuse it? Do I need to buy another one to replace it, or will my new shocks come with a new nut?

 

[FORCED2DV8]

New shocks usually come with the new nut, you can always open the package and check, Unless your ordering them, Its a captured nut, ( I think that what they call it) so when you put it on it locks on, when you remove it its not able to lock as good, so they give you a new nut, I dotn see why you couldnt just use a lock washer though..