Only modify these fields if empty

If song is categorised as Classical then any fields listed here will only be modified if currently empty, this is in addition to any fields already added to the Only modify these fields if empty option on the Format tab

For example Classical releases often consist of a number of works on a single album and if you have manually used work numbering rather than album numbering you can protect this by setting this by adding Disc No, Disc Total, Track No and Track Total to this list.