In an earlier post from a couple years ago, you mentioned that line 145 of tpl_main_page.php could be modified to weed out unwanted search terms.

My line 145 shows:
$keywords = '';

I've noticed a few oddities that manage to pass through Google, like:
²®
but confound my Zen-Cart search engine so that no further items are located.

Is there a means to add these characters so that they can be ignored?

Great mod, BTW - thanks!