# The legend block

The legend block contains information on how the legend will be displayed for this visualization.

Take a look at [the legends section](/felt-style-language/legends.md) to see how it works.

These are the fields that each legend block can contain:

| Field name    | Description                                                                                                                                                                                                                                                                                                                                                             |
| ------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `displayName` | <p>Optional.<br><br>In categorical visualizations, a dictionary that maps from each category to what will be displayed on the legend.<br><br>In <a href="/pages/l19xNEDSN3qnKxQpzWjT">numeric</a> or <a href="/pages/hvXsaskqTHe4aJVaytZe">heatmap</a> visualizations, a dictionary that maps from the index of each class to what will be displayed on the legend.</p> |

{% code title="Example of a categorical legend" %}

```jsx
"legend": {
  "displayName": {
    "category-1": "Category 1",
    "category-2": "Category 2"
  }
}
```

{% endcode %}

{% code title="Example of a numerical legend" %}

```jsx
"legend": {
  "displayName": {
    "0": "-0.5", 
    "1": "0.5"
  }
}
```

{% endcode %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://developers.felt.com/felt-style-language/style-definition-blocks/the-legend-block.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.