0GDTEX.PVR
From Sega Retro
0GDTEX.PVR is the name of an image file typically found in the GD-ROM area of a Sega Dreamcast disc. It is a 256x256 resolution image typically drawn in the shape of a compact disc, used exclusively for the Dreamcast's audio CD player. If an 0GDTEX.PVR file is found, the standard disc image is replaced with a customised one.
Having this file on the disc was optional, though many Dreamcast developers and publishers included one regardless, even in cases where there was no CD audio stored on the disc to listen to. There was no mandate for the 0GDTEX.PVR image to match the design of the real disc, only that it obeyed the standard ethics guidelines that all visual material had to conform to.
Despite the console's support for this feature, most Dreamcast have an audio track advising against playing a Dreamcast disc in an audio CD player. This is because older (and cheaper) players may only conform to the Redbook CD standard, so may interpret the CD-ROM data on track 1 as audio, which may result in loud, distorted noise that can theoretically damage speakers. Most modern CD players (including the Dreamcast) simply skip track 1 or play silence.