By default, Indie Website comes with two taxonomies: Categories and Tags. Custom Taxonomy, such as Deep Dives are available for publishers on Grow and Scale. Please reach out to Indiegraf Support to help setup a Custom Taxonomy for you.
Custom taxonomy allows you to organize a group of posts uniquely. This is especially common for long investigative series and guides, where each custom taxonomy holds many topics, and many topics accommodate a variety of articles.
To add a new series to a custom taxonomy, click on Posts > Name of your custom taxonomy. In this example, it's called "Deep Dives".
Once the custom taxonomy is added to your website, the option will appear on the post sidebar:
