Result Type: Number
Definition: Given a tax code and a date, returns the tax rate for that code on that date.
Returns the rate for the "G" taxcode as at today, for example
Returns the rate for the "G" taxcode as at 1st January 2010, for example
Note: Because the rate is determined by the ChangeOver Date for the tax in the Tax Rate table, the function is not able to determine the correct rate for tax changes prior to the date of a tax change (if any) before the last tax rate change.