When you create or edit a blog post, there's a panel on top of your tool bar where you can enter additional information for your post. Click to open it.
Enter a single word or a short phrase into the kicker field to classify your news thematically. This line will be visible in addition to the regular title within news overviews.
Please note: The kicker line is shown within the news item itself, and in news overviews that come with the macros of the Enterprise News Bundle. Any standard Confluence macros or macros of other plugins that show blog posts will ignore the kicker line.