Although these forms of Custom Field may still be used, since FileWave 12.7 additional new methods of Custom Fields have been introduced. The newer form allow for backward compatibility to these older Custom Fields, but provide much greater flexibility and would be recommended. Details on these may be found here:
Let's say you are using FileWave Integrated Inventory and you want to collect inventory data fields that FileWave does not report yet (you can check if you field is supported in the component list when you edit a query). The solution is to use the custom inventory fields introduced in FileWave version 7.0.0. There are 20 fields for each data type : String, Integer, Boolean, Date. Starting in version 8.5 the FileWave Client can accept input.