media [html5]

This attribute specifies the media which the linked resource applies to. Its value must be a media query. This attribute is mainly useful when linking to external stylesheets by allowing the user agent to pick the best adapted one for the device it runs on.

Usage note:

In HTML 4, only simple white-space-separated list of media description literals, i.e. media types and groups, where defined and allowed as values for this attribute, like print, screen, aural, braille, ... HTML 5 extended this to any kind of media queries, which are a superset of the allowed values of HTML 4.
Browsers not supporting the CSS3 Media Queries won't necessarily recognize the adequate link; do not forget to set fallback links, the restricted set of media queries defined in HTML 4.
