Not using payroll, how to differentiate between Salary and hourly employees?

We are not using the Payroll module. Not using this module, how do we setup employees to be salaried or hourly?

During some jobs, there are employees which are salaried and some of which are hourly, is there a way to differentiate the 2?

Suggest to use Employee Codes with some prefix, like S and H to distinguish them easily.