Poll: Precede Questions With "Ask HN:"?

Lately I've been noticing more and more 'ask' submissions without the "Ask HN:" leader in their title. I figured this was mostly newer users making submissions and thought about making a post requesting that people do that, for consistency. However I also realize that most self-posts live in the 'ask' page, which makes it less important to differentiate them in the title.

So my question is: Do you think that it should still be customary to start question posts with "Ask HN:" or the like?