HTML and track and default properties
The default property defines the track that is used by default in the video element, and if you have a better track selection, set the default property for it, which can be owned by only one track element in each media element.
Here's a video element, one of which has one of the two subtitles that is default:
<source src="forrest_gump.mp4" type="video/mp4">
<source src="forrest_gump.ogg" type="video/ogg">
<track src="subtitles_en.vtt" kind="subtitles" src
label="English" default>
<track src="subtitles_no.vtt" kind="subtitles" srclang="no"
label="Norwegian">
</video>
Browser support
Internet Explorer 10, Opera, and Chrome support default properties.
Definitions and usages
The default property is a boolean property.
If you use the default property, you specify that the track should be used if the user does not select a different track.
The difference between HTML 4.01 and HTML5
The label is a new HTML5 label.
The difference between HTML and XHTML
In XHTML, the property does not allow an introduction, and the default property must be defined as: slt;track default."
Grammar
HTML