[Koha] Question on search.pl sort options

Hello all, I remember that one of the sort options in /cgi-bin/koha/catalogue/search.pl was sorting by call number. Examples may still be found at http://lib.zilcc.ru/cgi-bin/koha/opac-search.pl and http://lib-2dim-kalam.thess.sch.gr/cgi-bin/koha/opac-search.pl but also at https://koha-community.org/manual/18.11/en/html/searching.html I know that the examples above are OPAC searches but I remember distinctly that the sort by callnumber was an option in intranet search as well. Now, in the current koha version the sort by callnumber option has been changed to sort by Class number. I've searched bugzilla and found no mention of such a need, to change sort options that is. Is the change documented somewhere? kind regards, Manos Petridis