This template will convert a system ID to the proper named category. The first and only parameter takes the system ID; applicable IDs are listed below. The template simply outputs the corresponding category as plain text.
To add an ID, simply add it to the list. Make sure everything's correct, and add in all the sensible synonym IDs as extra cases, making sure that all cases are lowercase. Once that's done, update Template:Syscat/ID documentation, adding the new ID.