Since end July 2017 a lot of covers and screenshot were added to RetroX, and more artwork is being uploaded to fill the possible gaps.
A common question is what kind of names are needed for RetroX to match a game with its artwork, use this document as a reference of how the name matching works.
The basic operation is to normalize the name removing any part of it that may be present or not when referring to the same game. All the text inside the following characters are removed from the name: [, ], {, }, (, ). Then lowercase is applied and only alphanumeric characters are preserved: 0-9, a-z.
Following there are some examples of original names turned into a matching code:
Street Fighter II (JAP) -> streetfighterii Street Fighter II (EUR) -> streetfighterii Bishōjo Janshi Suchie-Pai -> bishjojanshisuchiepai F1 Racing [!] (J) (V1) -> f1racing F1 Racing (J) (V2) -> f1racing Advanced V.G. -> advancedvg Gunple: Gunman's Proof -> gunplegunmansproof
The final code is then used to find the matching artwork. Note that at this point regional information is being removed and only one version of the artwork is used regardless or the region, that may change in the future
DOS and multidisk games
These games have many files for just one game, in this case the folder name is used as the game name.
MAME
These games have already a standard code, that game code is used instead of the matching described above. Some games are different versions of the same game, in that case if there is no artwork for the game, the artwork for the parent game is used.
Currently there are still a lot of MAME games without screenshots, they are being uploaded progressively.