[Koha-devel] Sort by title. Based only on Title or also on Title-cover ?

Hi, reading from etc/zebradb/marc_defs/marc21/biblios/biblio-koha-indexdefs.xml I see that from 245 $a are crerated two indexes: Title and Title-cover: <index_subfields tag="245" subfields="a"> <target_index>Title-cover:w</target_index> <target_index>Title-cover:p</target_index> <target_index>Title-cover:s</target_index> <target_index>Title:w</target_index> <target_index>Title:p</target_index> <target_index>Title:s</target_index> </index_subfields> Sort by title (A-Z) and (Z-A) in opac are based only on 'Title' Zebra index or also on Title-cover ? It is not clear for me. Bye Zeno Tajoli