In Ultimate SEO the feature is listed as: Filter Short Words

I think it helps to control the appearance of the url. Let's say the product name is fairly long with numbers and short words in it like:
'Trendsetters' Handbag Placecard Holder & Frame (Set of 4)

Special characters get already filtered by another setting. Now maybe I don't want stuff like "of" "to" "4" (numbers) in the url to not make it even longer?

Is this essential? Don't know but search engines don't look at these short words in searches. So maybe this can eliminate unnecessary stuff out of the url?

I see your point.... for simplicity maybe it is not absolutely needed. If it is easy enough to implement, it is on my wish list. It would help to have the same url's as I have now with Ultimate SEO. This could help other people to switch over to Simple SEO.

I have been thinking.... how difficult would it be to have the full control over what the url will look like (except the unique product ID at the end)? I have seen carts like Volusion that allow a customer defined url for each product. Is this out of question for Zen? Sorry if this goes beyond the goal of "Simple" SEO.