You should be able to highlight and copy category descriptions on past events
Currently, if an event has become read only, you cannot copy the descriptions for any of the categories found in setup. You should be able to copy them to paste into another event. There isn't a report that shows the descriptions listed very easily.
Erica Hunt commented
This would be a great advantage for using RSA year over year. All attributes should have the ability to copy and paste from prior years events.