The Work Breakdown Structure (WBS) defines the actual activity for which an employee is recording time and expenses. The WBS allows for 4 levels. The default labels for the WBS are Main WBS, Level 1, Level 2, Level 3, and Level 4 ; these labels are client configurable in Systems Labels under System Options in within Admin. Additionally, DATABASICS Time and Expense allows the creation of Types at Levels 1 and 2 of the WBS. For example, if Project is Level 2, the client may wish to have such Project types as Fixed Cost and Time and Materials.
...
All WBS levels have a billable flag. If a timelinetimesheet's time code and all WBS levels are billable, Time regards the timeline hours as billable. If either the time code or any part of the WBS on a timeline is not billable, Time regards the timeline's hours as not billable.
...