// Find deleted text that starts and ends with newlines which just means, a line (or a chunk) was removed before the next one (internal newlines don't matter)
$newStyled = preg_replace("/\n<del>[^<]</del>\n/", "\ndelline>", $newStyled);
// Find deleted text that starts on a newline, has newlines in it, and ends on another line with more stuff behind it
$newStyled = preg_replace("/\n<del>([^<]*\n[^<]*)</del>/", "\ndelline>delcode>", $newStyled);
// Find deleted text that starts on a line with more stuff in front of it, and ends before another line
$newStyled = preg_replace("/<del>([^<]*\n[^<]*)</del>\n/", "delcode>\ndelline>", $newStyled);
// Find deleted text that starts on a line with more stuff in front of it, and ends on a line with more stuff behind it, and has newlines in it
$newStyled = preg_replace("/<del>([^<]*\n[^<]*)</del>/", "delcode>\ndelline>delcode>", $newStyled);
// Find deleted stuff, and newlines no longer matter
$newStyled = preg_replace("/<del>[^<]</del>/", "delcode>", $newStyled);