You can use Markdown in various places, for example in info.description, in your tag descriptions, in your operation descriptions, in your parameter descriptions and in a lot of other places. We’re using GitHub-flavored Markdown. What’s working here, is probably also working in the API reference:

• bullet lists, numbered lists
• italic, bold, striked text
• accordions
• links
• tables
• images
• …

Have a look at our OpenAPI example specification to see more examples.

Note: Not everything is supported in all places. For example, you can use images in most places, but not in parameter descriptions.