Category Mapping for the PDF Templates can be found in Settings > Personal Settings > Category Mapping
This page is for mapping TriNet Expense categories in the template you have selected. By default, all of your categories will be already setup so nothing will need to be changed.
You can change where one of your custom categories appears in the report template on this page. You can also select the AUTO MAPPING button to have TriNet Expense instantly do the mapping for you. Make sure you choose the correct template in the drop-down provided first.