> From: Helen Borrie
> Hint: if you are referring to the gds codes in an ON EXCEPTION GDSCODE...
> structure in PSQL, you need to omit the "isc_" prefix from the constant
> name. This isn't documented anywhere except in the Using Firebird manual
> and it is there thanks to Ivan Prenosil's "inside knowledge".

The credit should go to Rey Rex, who discovered and published
this trick in IB list five years ago.

Ivan
http://www.volny.cz/iprenosil/interbase