Index and Dat Codes should do what you are after, but it needs to be a full long description based on the index code. If you are looking to build a long description based on many different fields, then you can add the fields to one of the required tables like materials. Then as you build your long description, you point to that table and pull in the data. I haven't found a way to create a custom table for this and we just use one of plant's required tables.