Field help (RUBDEC)

Specify the calculation rounding of employee's and employer's amounts of the heading.
For further information, refer to the arr() function. 

The rounding at 9 has a specific meaning. It is used to truncate the number. For further information, refer to the fix() function. 

If this field is left blank, these amounts are rounded based on the local currency. A heading with a rounding inferior to the rounding of the local currency cannot have the payroll MO setup.