We are trying to index punctuation as much as possible, e.g. http://duckduckgo.com/?q=%24_
However, most of the APIs we use to help generate results don't, and so it can be a bit sparse in that regard. That's why in the example search you don't see any traditional looking results below our Zero-click box.
Our Zero-click Info index does index full punctuation. As it is built out further, more and more searches with punctuation should return relevant results.
Our Zero-click Info index does index full punctuation. As it is built out further, more and more searches with punctuation should return relevant results.