Lost Releases covers all official digital and print media items published in the Silent Hill, Resident Evil, and Dino Crisis series. Counterfeit and pirate items are not covered. Whether an item is official or not may not be clear for certain magazine demo discs and similar items. Currently, the following promotional items are considered official or licensed: Items published directly by the developer or any of their licensed publishers (example); items published by the console manufacturers, Sony, Nintendo, Sega, etc. (example); or items licensed by the console manufacturers (example).
The second category is included as it is assumed that the console manufacturers have agreements with the publishers to use the contents. For example, Sony would receive trailers and demos directly from Capcom to include with the Official PlayStation Magazine demo discs. The third category is included because console demos need to be licensed by the console manufacturers.
There are some cases where the contents appear to have been recorded by the magazine staff, such as trailers filmed at conventions or gameplay recorded in the office. This German demo is a good example of the latter. It is difficult to say whether such items are official or not. Perhaps they had permission to record gameplay videos and put them on the disc. Capcom may have sent out preview or review builds of the game and allowed the the magazines to use videos and screenshots as they wished. However, does a loose permission mean that the item is licensed? While it is not a pirate item, if there is no formal license the item should perhaps be considered unofficial. These items are still included on the site.
There is a fourth category of promotional discs covered on the site, which is not covered by any of the criteria above. These discs are labeled 3rd party samplers, and came with random magazines. In some cases it is very obvious that the videos came directly from the developers and should be considered licensed, while in many cases it is difficult to determine. For practical reasons all discs which does not mean any of the three criteria are simply grouped together in the 3rd party sampler category. Again, while many cannot be considered official or licensed, they are not pirated, illegal items. The developer allows magazines to use these videos, even though there may not be a formal license agreement.
Promotional discs, whether playable or video-only, are sent to magazines for review and preview; sent to shops to display trailers or let people try the game in-store; sent to shops for them to order the game; included with another game from the same publisher inside the game package or as a pre-order bonus; included with a gaming magazine; handed out for free in shops or at conventions; or sent to various members lists like for example PlayStation Club and Sega Partners in Japan.
Often, especially in North America and Japan, the press are not sent factory manufactured promos and demos for review and preview. They are sent prototypes on recordable media. Prototype is a general term for various builds on recordable media. They are made for in-house use (development, testing, localization), review and preview purposes as mentioned, and as playable builds to bring to events such as E3 and TGS. Lost Releases does not cover prototypes.
The image-ready master disc, which is on recordable media, is loaded into a computer and transferred to a glass master by a laser beam recorder (LBR). The LBR also writes the digital matrix code to the glass master. This code includes LBR IFPI codes, internal pressing plant job numbers, catalog numbers, layer numbers on dual layer DVDs, and more. The LBR IFPI codes always start on L, followed by three or four alphanumeric digits. It identifies the particular LBR machine which was used to master the glass master.
The glass master is coated with metal, and electroplated with another metal layer in a ion bath. The metal layer is separated from the metallized glass master, this is now called the father. It is a negative image of the digital information, and can be used to press discs. Instead, it is plated again to produce a mother. The mother can again be plated many times, to produce multiple stampers used for disc replication.
Additional information, stamper numbers, can be added to the matrix codes on all the three metal plates. This code is used to identify the metal plates used in the production of a particular disc, to easily identify the source of possible errors. These stamper numbers look different to the digital matrix code, as they were physically etched into the metal. Two discs which have identical digital matrix codes, but different stamper numbers, will still contain the exact same digital information.
During pressing, a second IFPI code may be moulded into the disc. This IFPI code is placed close to the spindle hole, and identifies the pressing plant as well as the specific mould used to press the disc. The mould IFPI contains four or five alphanumeri digits. The two first digits, or three in the case of a five digit code, identify the pressing plant, while the last two identify the mould. In other words, the mould IFPI code does not give any information about the digital contents on the disc nor about the metal plates, it only shows exactly where the disc was made. This list can be used to identify country of manufacture by mould IFPI codes.
The various parts in the matrix code are shown in image 1. The matrix code shown is from Resident Evil Dead Aim (SLES 51448 0920947).
The image-ready master disc itself does not contain a matrix code. The matrix code is decided by the operator of the LBR. The same image-ready master may frequently be used to create multiple new glass masters. This could be to manufacture several glass masters at the same time to speed up the manufacturing process, or to manufacture a new glass master for a later reissue. These glass masters are then numbered in the the digital matrix code, which means that discs made from the same source may still have slightly different matrix codes. In this case the contents can be determined to be identical by identifying the particular parts of the matrix code. For example, if a disc has an internal job number DIDX-01234 followed by a 1, and another has the same job number followed by a 2, the digital contents will be identical.

1. Various matrix and IFPI parts