Today, these files are mostly of interest to digital historians or enthusiasts of "abandonware."
: The specific expansion or special edition of the title you are seeking. : These are disc image file formats
Back in 2006, KISS was at the forefront of the "3D character creation" subgenre. Unlike traditional visual novels, Custom Slave Fantasy allowed players to customize the appearance of 3D models. While the graphics appear dated by modern standards, this game was a mechanical predecessor to the massive Custom Maid and Custom Order Maid series that still dominate the market today.
A file labeled "Plus" suggests this isn't just the vanilla game. It is likely a "repack"—a custom installer put together by a pirate group that includes the base game, official patches, and perhaps a selection of the most popular fan-made mods. It represents the labor of love by the community to fix and expand upon the original product.
It is highly likely this string refers to a specific game released on that date. If you can identify the actual game title (for example, many popular JRPGs or action games were released on that day), I would be happy to write a blog post about: