CCS media type

Reconized Media type

all

Suitable for all devices.

braille

Intended for braille tactile feedback devices.

embossed

Intended for paged braille printers.

handheld

Intended for handheld devices (typically small screen, limited bandwidth).

print

Intended for paged material and for documents viewed on screen in print preview mode. Please consult the section on paged media for information about formatting issues that are specific to paged media.

projection

Intended for projected presentations, for example projectors. Please consult the section on paged media for information about formatting issues that are specific to paged media.

screen

Intended primarily for color computer screens.

speech

Intended for speech synthesizers. Note: CSS2 had a similar media type called 'aural' for this purpose. See the appendix on aural style sheets for details.

tty

Intended for media using a fixed-pitch character grid (such as teletypes, terminals, or portable devices with limited display capabilities). Authors should not use pixel units with the "tty" media type.

tv

Intended for television-type devices (low resolution, color, limited-scrollability screens, sound available).

Media type names are case-insensitive.

Excerpted from w3.org

Example of adding *.css to a media type:

; Add a stylesheet for all media
stylesheets[all][] = theStyle.css
; Add a stylesheets for screen and projector media
stylesheets[screen, projector][] = theScreenProjectorStyle.css

Excerpted from Drupal CSS