The Category parameter lets you classify traces any way you want, including leaving the Category parameter blank. For example, give your reloads the category "Reloads" and give other traces categories such as "Rifle" , "Handload", or "Rimfire". Category is shown as the second column in the Trace catalog, so when you want to load a trace of a particular category, click on the column's heading to sort by category, scroll to the category and find the record you want to load.
On the Trace window, note the down arrow button just to the right of the Category parameter. You can either enter a category directly into the parameter or click the down arrow button to select from a list of current categories. The program maintains a list of all the categories being used by all the traces in the trace file. To add a new category you just enter it into the Category parameter and save the trace. If you delete all the traces of a particular category, that category will be removed from the list. You can change the category of a trace by editing the Category parameter and then saving the trace. You can also use the Change Trace Category tool to change the category of many traces at once.