Andrei,
it will be possible in a future release to create a field for disc MATRIX (the id code printed in the inner circle of the cd, which often is different from Disc Number) like you did for the BARCODE in the Release Information box properties?

Using a custom textbox for Disc Matrix, every time I have to insert a new one, the textbox will generate automatically a combo with all the other values present in the database, and this is a loss of time as Matrix is almost unique like the barcode and there will be no need to load all other values from the database.

Thanks
Emanuele