I've seen a number of blog posts that have eye-catching banners at the top that indicate that the post was either updated with new info, or say that the post is

I've seen a number of blog posts that have eye-catching banners at the top that indicate that the post was either updated with new info, or say that the post is outdated with a link to a follow-up entry. Those are always nice to see since it shows that not only is the info up to date, but also that the author cares enough to keep their posts relevant to their audience