HTML Guide for projection
The projection media type was deprecated in Media Queries 4.
Media types describe the general category of a device, for example screen, print and speech.
CSS 2.1 and Media Queries 3 defined several additional media types (tty, tv, projection, handheld, braille, embossed, and aural), but they were deprecated in Media Queries 4 and shouldn’t be used.
The media attribute on the link element cannot use the deprecated value projection; only valid CSS media types should be specified.
The media attribute specifies what media/device the linked resource is designed for, using a media query or a list of valid media types. In modern HTML and CSS, commonly accepted values include all, print, and screen.
The value projection was intended for projectors but has been deprecated and is no longer recognized by browsers or the HTML standard. To ensure validity and compatibility, remove projection and use only accepted types such as screen and/or print.
Incorrect example (with deprecated value):
<link rel="stylesheet" href="style.css" media="screen, projection">Correct examples:
<link rel="stylesheet" href="style.css" media="screen"><link rel="stylesheet" href="style.css" media="screen, print">If you intend your stylesheet for screens and print, you can use both screen, print; for only screens, use just screen. If the stylesheet should apply to all devices, you can omit the media attribute or use all:
<link rel="stylesheet" href="style.css">or
<link rel="stylesheet" href="style.css" media="all">