Can currently search on the isbn with the 020$a mapping It would be useful to have another index on the invalid-isbn mapping to the 020$z only https://www.loc.gov/marc/bibliographic/bd020.html
Aleisha, please, cf. bug 36574. The plan discussed during Hackfest with Nick, Katrin, ans Sonia (for UNIMARC) is as follows: 1. Add a second index for all ISBNs, isbn-all (and NOT to add one only for cancelled ones--we have discussed also this idea). This gives one already the possibility to perform a general search (i.e. by keyword) with a cancelled ISBN. This is done in the bug 36574. 2. Add a system preference to be able to decide if an ISBN-search would be performed only in valid ISBNs ($a) (isbn search field) or all ISBNs ($a + $z) (isbn-all search field). This is to be done. (We plan to do this in within a month.) An analogous approach could be used also for ISSNs (bug 36727), possibly with the same system preference.
*** This bug has been marked as a duplicate of bug 36574 ***
Cool thank you!