In restaurant you also define rate of taxes according to your requirements. If you define your tax rate you are requested to click on this link as; Master>Tax
As you click following window will come to you as
In the above shown window you see also existing Tax rate and tax description. Let know both these.
Tax Description: Type of the tax like VAT 14%, exempted etc. Give the percentage alongwith so that it will be easier for you to identify how much tax you are charging to the customer.
Tax Rate: Percentage value of the tax( 0% for exempted).
Double click on the row to edit the Taxes.