Section 1.15.1.1 Display856uAsImage needs updating. Under Values, the "Both Results and Details pages" option says "Not implemented yet", sometime before version 3.12.4 this was implemented when the XSLT option for the results page was fixed. This should be changed to "Both XSLTResultsDisplay and XSLTDetailsDisplay need to be on for this preference to work". Likewise, further down the "Results page only" says "Not implemented yet", this should be changed to "XSLTResultsDisplay needs to be on for this to work". Additionally, there is text at the end of the description that reads "in the current window or in a new window depending on the value in the system pref OPACURLOpenInNewWindow". On my installation the system pref OPACURLOpenInNewWindow does not control this action in the Staff Client, and I don't find a corresponding option in the Staff Client area. I think the description should be modified to remove that phrase. This started to work at some point because someone fixed the Results XSLT file for the staff client (at least the marc21 version). I am not sure what release that occurred in, so there may be some older doc that needs updating also. I am on version 3.12.4 and am reporting on the version 3.12 doc. It looks like the 3.14 doc is the same. I assume this feature still works in 3.14, assuming is always dangerous though. :)
This feature doesn't work for me in the staff client at all, with or without XSLT enabled. Not for the detail page and not for the search results page. In the OPAC it appears to work only on the detail page with XSLT enabled.
Owen, it still works on my install. I am on version 3.16.00.000 . One thing about this feature, though the default shows "Both" after it is installed, I think it is in fact set to "Neither". Try changing the setting to "Neither", then back to "Both" and see if that makes a difference. XSLT has to be set to "default". When I wrote this we didn't have the option of designating a custom XSLT, and I implemented the feature in the built in stylesheet.
To make it works, you need to set 856$q=img (or image, gif, etc.) This feature seems to correctly implemented for MARC21 only: git grep -l Display856uAsImage | grep MARC21 MARC21 koha-tmpl/intranet-tmpl/prog/en/xslt/MARC21slim2intranetDetail.xsl koha-tmpl/intranet-tmpl/prog/en/xslt/MARC21slim2intranetResults.xsl koha-tmpl/opac-tmpl/bootstrap/en/xslt/MARC21slim2OPACDetail.xsl koha-tmpl/opac-tmpl/bootstrap/en/xslt/MARC21slim2OPACResults.xsl UNIMARC koha-tmpl/intranet-tmpl/prog/en/xslt/UNIMARCslim2intranetDetail.xsl NORMARC: koha-tmpl/intranet-tmpl/prog/en/xslt/NORMARCslim2intranetResults.xsl koha-tmpl/opac-tmpl/bootstrap/en/xslt/NORMARCslim2OPACDetail.xsl koha-tmpl/opac-tmpl/bootstrap/en/xslt/NORMARCslim2OPACResults.xsl
I made the changes in the manual. Just waiting for a merge in gitlab. https://gitlab.com/koha-community/koha-manual/merge_requests/149