You mean layer descriptions?
Take your first part and delete the model, then save it as a template part. Use this template to start all your new parts from. Set it to RO, so you don't overwrite it.
"Wildfires are dangerous, hard to control, and economically catastrophic."
In addition to what Ben said, you could take your first part file, delete the model, then import the new one, then rename. That's about the only way if you've already started modeling.
If you copy the part with the layer category descriptions possibly to another file name and then delete all the contents then you will have an empty part file with the correct categories. If you then import that file into any other file the categories will be added.
Most people use template parts for that kind of thing these days but this trick is still handy to know if you have an existing part and want to save some time.
