Accounts: How to handle tickets you don't want customer to see?

Accounts: How to handle tickets you don't want customer to see?

What is the best way to handle tickets you don't want an account to see?  For instance, there is time associated from a Purchase Order generated.  Engineers still need to assign time to work done; but I don't want customer to see the detail of this flat rate work.  Do I create another account called:  'Same Account Name - our eyes only' type of thing......I think it would work for billing purposes since it would be split from regular ticket billed items.  Input? 

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