'''[RATEDESC]''' - name of the rate
'''[PRICE]''' - Value in price field(number entered in the price field of the booking)
'''[PRICE:10%]''' - Percentage value of Price
'''[INVOICEPAYMENTS:-100]''' - invoice sum of all payments with offset
'''[INVOICECREDITS]''' - invoice sum of all credit items (negative items)
'''[INVOICECREDITS:50%]''' - invoice sum of all credit items with percentage multiplier
'''[INVOICECREDITS:-100]''' - invoice sum of all credit items with offset
'''[INVOICEDEBITS]''' - invoice sum of all debit items(positive items)
'''[INVOICEDEBITS:50%]''' - invoice sum of all debit items with percentage multiplier