Your two posts were, " the smallest snake for a small enclosure." Hence, my first question to you is, what is small to you? That you never clarified. And yes, many people will assume you are referring to the typical 'small' description for snakes: a 10 gallon. Secondly, your posts clearly stated that you are looking at both commonly found as well as anything not too hard to find. Again, there lacks clarity so many of those who posted mentioned the commonly kept species (ie corn) as well as not (ie housenakes). So just the same, I mentioned both.
In other words, if you are seeking a specific answer, ask a more specific question. What is considered 'small' to you.
Lastly, while you may be one of the few who don't stuff their snakes in crowded tanks, there are unfortunately many who do. Knowing nothing about you from your posts, yes, I will assume because that is what people naturally would do. If you don't want that assumption, then make it clear to the reader from the get go.