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.