While the new design manager in SharePoint 2013 is nice, it is taking me some time to familiarize myself with how to do things that I knew how to do in 2010, but is now a bit different in 2013. For one thing, I'm used to working with master pages directly, not with just the HTML used to format the page. When the design manager functionality logically splits the master page "goo" from the HTML, it leaves behind commented out tags that start with <!--MS:--> and <!--ME:--> that show in the HTML. Markup inside these tags is in some cases what you would find in the final master page. In other cases it is a bit different.
So when I started trying to figure out how to hide the ribbon from anonymous users as I've done in the past, it was a bit perplexing to sort out where in the HTML file does the markup corresponds to the ribbon.
After some searching in the out-of-the-box oslo.html file, I found this area:
When I added the following markup enclosed in the <!--MS:--> and <!--ME:--> tags, the design manager created the corresponding master page with the correct functionality of hiding the Ribbon for an anonymous user: