We run into this issue with libraries who are not using EDI, get their items pre-processed by a vendor, and want on-order items to show in the catalog: - MARC records are imported for on-order titles - On-order items are created - Vendor sends final MARC records including 952 tags with barcode, ccode, location, etc - Final records match to existing records at the bib level, but cannot match at the item level - Item records need to be manually touched either to add final details to on-order items or to delete on-order items in favor of newly-created final items The vendor cannot give a barcode number when supplying on-order records and (without EDI) Koha doesn't have a way to send the on-order item numbers to the vendor to be included in the final item info. I'm imagining something like a syspref that lets us say "if an item has notforloan of [X], then allow item overlay without matching an itemnumber or barcode." But as I type that I suspect there are a lot of ways it could go bad.
I think this is worth thinking it over some more. Maybe it could work like this: - match not-for-loan = on order - match home or holding branch if possible - match itemtype if possible... So it tries to find the best match and falls back to the next best?
Maybe there could be 'Item matching rules' similar to what exists for bibs - a notforloan status picker could be built in, plus options to set whatever other criteria a library wanted to use.