What do all the other columns on Parts Categories do, and what information is contained in them.
Engineering Part Number, Sales Part Number, Part Name and Quantity Columns all help to identify each item and how many of that item exist at that specific part of the hierarchy (eg, the same part might appear multiple times in the file if that same part is used at multiple levels of the product hierarchy).
The Type column helps you to see whether the item is an assembly or individual part to make it quicker and easier to apply your desired Parts Categories hierarchy to the file.
Hint: You may/may not want to Combine Assembly with Lowest Level Category on Assemblies within your hierarchy here. Using the “Type” Column can help you figure out where you want hotspots and at what level.