Mentions in Blogger
To use this feature, you first need to upgrade your Blogger profile to a Google+ profile.
Mentioning someone is an effective way to let them know that you're
referring to them in your blog post. You can mention a person, or a
Google+ page, even if they don't follow you. Depending on how they've
configured their Google+ settings, they might receive a notification
about your mention after you publish the post.How to mention others
To use this feature, just type "+" or "@" followed by the name or page. As you’re typing, you'll see a list of names appear below. You can click to select the person or page that you'd like to mention.If you've configured your settings to share your blog posts to Google+, you'll see that the names of the people you've mentioned in your post will be automatically added to the share box.
Related: Learn more about mentions in Google+.