What are HTML 4 media specifiers

Can some one explain to me what HTML 4 media specifiers are? Is there docs that explain this?

Solution

OK, you mean MediaDesc

Attribute values of type MediaDesc are media descriptors — a comma-separated list of media for which the linked resource is tailored. Media descriptors are case-sensitive.

The following media descriptors are defined in HTML 4:

screen, for non-paged computer screens;

tty, for fixed-pitch character grid displays (such as the display used by Lynx);

tv, for television-type devices with low resolution and limited scrollability;

projection, for projectors;

handheld, for handheld devices (characterized by a small display and limited bandwidth);

print, for output to a printer;

braille, for braille tactile feedback devices;

aural, for speech synthesizers;

all, for all devices.

from http://htmlhelp.com/reference/html40/values.html

At first I thought you were asking about CONTENT types, like text/html, image/jpeg, audio/mpeg, video/quicktime, text/css, and text/javascript.

See http://www.iana.org/assignments/media-types/index.html