Three letter search?

Google can't index members only sections of the site like the trading Post.

We can decrease the minimum length, but it becomes risky. For a 3 letter word, imagine someone searching the, or and. We'd be indexing and sorting over a million posts each time to cover it. And the results wouldnt be relevant anyways.

Are you able to exclude words like "the" and "and"? Or would it start getting confused if someone searched lathe or sand?