: Modded or compressed game files (like those for Jet Moto or other retro titles) sometimes use "J&M" or similar shorthand in archive names.
: You can often right-click the file and select Extract All or use the open-source 7-Zip tool to open it. J&M123.7z
: Developers often use such names for temporary ZIP or 7z backups. : Modded or compressed game files (like those