[Koha] 999 $c and $d, and limits on nu

In a Koha item record, should the 999$c (BIBLIONUMBER) and 999$d (BIBLIOITEMNUMBER) fields always be identical? We've had some issue show up with the newest LLEK testing where the 999$c and 999$d fields don't match in some records and it causes a situation where users may see a summary record for one item, but clicking on the title link leads to an entirely different item. Why there are even two different fields for biblionumber and biblioitemnumber if the field data is always supposed to be identical for those fields? -- Stacy Pober Information Alchemist Manhattan College Library Riverdale, NY 10471 stacy.pober@manhattan.edu