Processing order of pretax deductions in payroll process (when Iterative Processing enabled)

Hi,

This is to understand how pretax deductions are processed when iterative processing is enabled.

We have requirement to collect arrears for pretax deductions, so wanted to confirm the processing order of pre tax deductions in payroll run (when Iterative Processing enabled).

For example, how are the deductions collected when an employee have - Medical, Dental, Vision, HSA, FSA, 403, 457 & Nonqualified Deferred.