Currently the rcn index used to search for volumes contains all $w subfields from 7xx and 8xx linking fields. In some cases this is too broad, even tho we are additionally limiting to monographs. Example: Search volumes will also find - records with a 775$w - other edition - records with a matching 780/785$w - preceeding or succeeding ... A specific index for searching volumes (rcn-volumes) should contain: - 773$w (we still need to limit to monographic, because these could also be analytcal links) - 800$w - 810$w - 811$w - 830$w Once the index is defined we can update the XSLT and the method for determining if the "Show volumes" link should be shown to use it and have a correct result list.