Paul asks:

The question is : what is the good behaviour ? * barcode IS mandatory => manage this in checker, the tools that checks that your DB is correctly parametered. * barcode IS NOT mandatory => change non-MARC part of Koha to accept empty barcodes.

At NPL, we have in the past used our catalog to store pieces of information that were not physical items, like names and addresses of local social agencies, and websites (before we had Koha). That would allow people to search for something like "poverty" and get hits not only on books about poverty, but websites about poverty and the names of local agencies that deal with poverty. If the catalog is used to store information that does not relate to a physical item, then the barcode should not be mandatory. However, I think the templates for adding and editing items should then be set to return a warning, in case someone mistakenly enters a physical item without a barcode. Stephen Hedges Nelsonville Public Library