tiptap/docs/src/docPages/api/extensions/underline.md

# Underline
Enables you to use the `<u>` HTML tag in the editor.

## Options
| Option | Type   | Default | Description                                  |
| ------ | ------ | ------- | -------------------------------------------- |
| class  | string | –       | Add a custom class to the rendered HTML tag. |

## Commands
| Command   | Options | Description              |
| --------- | ------- | ------------------------ |
| underline | —       | Mark text as underlined. |

## Keybindings
* Windows & Linux: `Control` + `U`
* macOS: `Command` + `U`

## Usage
```markup
<template>
  <div>
    <editor-menu-bar :editor="editor" v-slot="{ commands, isActive }">
      <button type="button" :class="{ 'is-active': isActive.underline() }" @click="commands.underline">
        Underline
      </button>
    </editor-menu-bar>

    <editor-content :editor="editor" />
  </div>
</template>

<script>
import { Editor, EditorContent, EditorMenuBar } from 'tiptap'
import { Underline } from 'tiptap-extensions'

export default {
  components: {
    EditorMenuBar,
    EditorContent,
  },
  data() {
    return {
      editor: new Editor({
        extensions: [
          Underline(),
        ],
        content: `
          <p><u>This is underlined.</u></p>
          <p style="text-decoration: underline">This as well.</p>
        `,
      }),
    }
  },
  beforeDestroy() {
    this.editor.destroy()
  }
}
</script>
```