Because GRS1 search/indexing was removed in 3.18, and record.abs is *only* used to configure GRS1, the following files can and should be removed: etc/zebradb/marc_defs/unimarc/authorities/record.abs etc/zebradb/marc_defs/unimarc/biblios/record.abs etc/zebradb/marc_defs/marc21/authorities/record.abs etc/zebradb/marc_defs/marc21/biblios/record.abs etc/zebradb/marc_defs/normarc/biblios/record.abs Furthermore, all comments in *-koha-indexdefs with line numbers pointing to record.abs can and should be removed -- these were inaccurate at best, and were a source of git conflicts at worst.
I think there are more remains of GRS1 indexing, as we haven't changed much of the code there yet. Like in the installer. Linking to an omnibus - bug 14302
*** This bug has been marked as a duplicate of bug 14302 ***