According to this DigiTimes article, some of the big makers of blank DVD media plan to ask the Japanese authorities to crack down on illegal use of so-called “fake” media codes.
Media codes are used by DVD recording devices to select appropriate settings and speed when recording DVD media. Such media codes need to be actively supported by the firmware inside a DVD recording device, and since including and testing a new media code for firmware costs time and money, many second/third-tier manufacturers use existing DVD media codes belonging to other well-known makers of blank DVD media instead of trying to get optical drive makers to include support for their particular media in DVD recording devices.
This practice is popularly known as using “fake” media codes.
From the DigiTimes article:
International brands of optical discs in the Japan market, including TDK, Imation and Verbatim, plan to ask Japanese authorities to ban the import of blank DVD+R/-R discs that pirate their M-Codes, which would affect some second-tier makers of optical discs in Taiwan because they are producers of a large portion of such DVD+R/-R discs, according to industry sources in Taiwan
Read more in the original article and discuss it here.