!("confirmed" in user_groups) & page_namespace == 0 & /* narrow down edits to just those dealing with references */ removed_lines contains "<ref" & /* this edit_delta ignores large blankings treated by another filter */ edit_delta >= -3000 & /* No added lines usually means a blanking which is dealt with by other filters */ length(added_lines) != 0 & !("#redirect" in lcase(added_lines)) & ( ( /* More opening ref tags are removed than added */ rcount("(<ref\b)", removed_lines) > rcount("(<ref\b)", added_lines) ) | /* OR */ ( /* More closing ref tags are removed than added */ rcount("(<ref\b[^>]*\>)", removed_lines) > rcount("(<ref\b[^>]*\>)", added_lines) ) ) & /* Exclude removal of references to Wikipedia */ count("//az.wikipedia.org", removed_lines) <= count("//az.wikipedia.org", added_lines) & /* If removed empty ref, probs OK */ count("<ref></ref>", removed_lines) <= count("<ref></ref>", added_lines) & /* ignore conversion between <ref> and </ref> */ rcount("</?ref>", removed_lines) > rcount("</?ref>", added_lines) & /* if they removed a probable comment with ref tag then its probs OK */ rcount("<!--.*</?ref>.*-->", removed_lines) <= rcount("<!--.*</?ref>.*-->", added_lines)