Hi! We have encountered an interesting behaviour and are not sure if it's a bug in Koha, in our data, or something else: We have a bibliographic record A where 830$w points to another record B (to the other records' 001 value, to be precise): A: 830$w = 12345 B: 001 = 12345 When Koha renders record A, it produces a link to B, but with a bad param: http://intranet/cgi-bin/koha/catalogue/search.pl?q=rcn:12345 Changing the param from 'rcn' to 'control-number' finds the correct record: http://intranet/cgi-bin/koha/catalogue/search.pl?q=control-number:12345 We're using ElasticSearch with default mappings. Looking into those, I see that there are defintions for record-control-number (rcn) and control-number. control-number points to 001, and rcn to various 7/8nn$w fields. Now it makes sense that the search for rcn did not find the value stored in record B.001, and why chaning the search to control-number finds the record. Which leads to my question; * Should we add 001 to the fields mapped to record-control-number? * Should we use a different field than 830w$? We are quite sure that we shouldn't, as the DNB is also using 830$w: https://portal.dnb.de/opac/simpleSearch?query=9783847703389 "Beziehungen: Die Andere Bibliothek ; Bd. 338", linking to (DE-101)015935620: https://portal.dnb.de/opac/opacPresentation?cqlMode=true&reset=true&referrerPosition=0&referrerResultId=%229783847703389%22%26any&query=idn%3D015935620 * Should we change the template to produce a link using a different param? Feels wrong, becuase it does make sense to link to 'rcn' and not to 'control-number'. Also we don't want to mess with the core Koha templates... Any ideas / pointers? Greetings, domm -- #!/usr/bin/perl https://domm.plix.at for(ref bless{},just'another'perl'hacker){s-:+-$"-g&&print$_.$/}