How to add "Suspend" ordering rule:
1) Under "Products" menu, on the left hand side of your builder
2) Select "Price Sets"
3) Double click on "Ordering Rules"
4) Click on the "+" button at the bottom of page
5) Select "Standard"
6) Rename to "Order Suspend"
7)Click on the "+" and select "Add Condition"
8) Select the conditions you wish to implement on this suspend ordering rule
9)Click on the "+" and select "Add Calculation"
10) Select from drop down menu "Suspend Order Processing"
11) Here you can add a message directing customer to change their order before it can be processed
Make sure to preview and test orders before publishing.