## Why is this an issue?

In order to make your site usable by as many people as possible, subtitles should be provided for videos.

This rule raises an issue when a `video` does not include at least one `<track/>` tag with the `kind` attribute set to `captions`, or `descriptions` or at the very least `subtitles`.

Note that the `subtitles` kind is not meant for accessibility but for translation. The kind `captions` targets people with hearing impairment, whereas `descriptions` targets people with vision impairment.

### Noncompliant code example

    <video id="video" controls preload="metadata">
       <source src="resources/myvideo.mp4" type="video/mp4">
       <source src="resources/myvideo.webm" type="video/webm">
    </video>

### Compliant solution

    <video id="video" controls preload="metadata">
       <source src="resources/myvideo.mp4" type="video/mp4">
       <source src="resources/myvideo.webm" type="video/webm">
       <track label="English" kind="captions" srclang="en" src="resources/myvideo-en.vtt" default>
       <track label="Deutsch" kind="captions" srclang="de" src="resources/myvideo-de.vtt">
       <track label="Español" kind="captions" srclang="es" src="resources/myvideo-es.vtt">
    </video>