Specifies the media type, chosen from the list specified
in the HTML4 spec at
<http://www.w3.org/TR/REC-html40/types.html#h-6.13>. At
present, only `screen', `print', `tty' and `all' are documented as being
recognised, but there's no reason why further ones couldn't be added
ad lib., or fancy games played here. For consistency, however, one
should probably stick to the list in the HTML 4 spec.
Type: string
Media type string, chosen from the HTML4 list of media types.