I all, I've read the mail on this thread rapidly. I just wanted to explain something : To support any MARC flavour, NO MARC TAG/SUBFIELDS ARE HARDCODED into Koha. So, you can move the koha fields that are mapped to 090 in the default configuration to ANYTHING YOU WANT. There is only 2 constraints : * The 2 koha fields MUST be in the same MARC tag. * No other subfield can be defined in this tag. It's only for koha internal use. I hope this is a good news for you, and hope you'll like more and more how Koha was designed :-) (Koha MARC DB design is @ Paul, Steve and Serguey iirc. You can see some benchmarks history in /marc/ directory of cvs) -- Paul POULAIN Consultant indépendant en logiciels libres responsable francophone de koha (SIGB libre http://www.koha-fr.org)