A video with two subtitle tracks. "English" subtitle is the default:
The default attribute is not supported in any of the major browsers.
The default attribute is a boolean attribute.
When present, it specifies that the track is to be enabled if the user's preferences do not indicate that another track would be more appropriate.
Note: There must not be more than one track element with a default attribute per media element.
The <track> tag is new in HTML5.
In XHTML, attribute minimization is forbidden, and the default attribute must be defined as <track default="default" />.
Your message has been sent to W3Schools.