# Principal box

The main box an element generates.

## What is a **principal box**?

The **principal box** is the main box an element generates; extra boxes like list markers hang off it.

```css
li { display: list-item; }   /* one principal box, plus a marker box for the bullet */
```

Level: Master · [More CSS terms at this level](https://www.ask-codey.com/glossary/subjects/css/master)

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/principal-box