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)