This came to my attention with Novelist Select, but it does not appear to only relate to that. Here's what I'm seeing: Issue 1: A MARC record shows the 020 $a as "9780345813602 (hardcover) :" (minus quotes). The Novelist Select section of detail shows as blank. Novelist support reports seeing that they're getting a 9-digit ISBN 034581360. When I inspect the Novelist Select section, Koha appears to be passing 034581360X. <div data-novelist-novelistselect="034581360X"> https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=15772 mentions that Novelist can't interpret 10-digit ISBNs ending in X and this seems to be consistent with that. Issue 2 (less problematic from a patron perspective): A MARC record shows the 020 $a as "9781408810552" (minus quotes). The Novelist Select section shows the expected results. Novelist support reports getting ISBN 1408810557 This is a valid ISBN for the title, but not the one on the record. When I inspect the Novelist Select section of the details page, Koha appears to be passing 1408810557. <div data-novelist-novelistselect="1408810557"> In both cases above, ISBNs used for Novelist Select are the same as used for gbs-thumbnail-preview, however the cover image is returned in both cases.
Koha converts ISBN-13 into ISBN-10 for looking up a lot of enhanced content. I think that Amazon can only use ISBN-10 so that might be the origin for this behaviour.
(In reply to John Yorio from comment #0) > Bug 15772 mentions > that Novelist can't interpret 10-digit ISBNs ending in X Not necessarily relevant to this bug report, but I don't think this is still the case. I can see Novelist content related to 10-digit ISBNs ending in X. https://search.myacpl.org/cgi-bin/koha/opac-detail.pl?biblionumber=6645