The mappings.xml file provides the matching mechanism to convert DITA topics to slides.

1. Open your PowerPoint template in in the PowerPoint application.
2. Click View > Slide Master.
3. Open Oxygen, and navigate to the unzipped com.jorsek.powerpoint plugin.
4. In the config folder, open mappings.xml.
   
   This file lists all the slide layout labels for the PowerPoint template. The plugin uses this mapping to convert the DITA topics to PowerPoint.
5. In PowerPoint, hover over the first layout below the theme master.
   The hover text shows the layout label, and whether it's used by any slides. We only care about the label.
6. In Oxygen, type that label into a mapping entry for both the source and the layout.
   For example, in the previous screenshot, the layout name is title_and_caption, so our mapping entry looks like this.
   

   Important: The mapping entries have to match exactly to the slide layout name. If they don't, you will get unexpected results when you try to publish the PowerPoint output.
7. Repeat this process until you've created a mapping entry for all of your slide layouts.
8. At the very top of the mappings.xml file, designate one of your layouts as the default mapping.
   In this example, we designate the title_and_content layout as the default. Don't use the basic title slide as the default; pick a different template instead.
   
   
   The plugin applies this template if it cannot find a matching template, based on the outputclass you specify on a topic. (Refer to Create PowerPoint-Ready Topics for a reminder on that configuration.)
9. Delete any extra mapping entries, but leave the stub mapping at the end of the file, for title_slide, alone.
   The publishing process needs this default template to properly create a slide deck.
10. Save your changes.