Filtering orders from being displayed on your site can be done in 2 different ways: 

1. By entering a specific value into Class Field 1-5 of the order.
2. By specifying an 'Order Type' that you'd like to exclude and assigning that type to the order.  

Filtering either Invoices or Purchase History from being displayed on your site can be done with the use of the PO Number. This filtering can be done by selecting a single character (typically a special character) and adding it to the PO Number of invoices and purchases that you'd like to exclude from your site. 

Your site will then look for any PO Number with the specified character included, and exclude the associated information from displaying.