ISO 8.3 refers to a standard for file naming conventions that originated from the ISO 9660 file system used in CD-ROMs. It specifies that filenames should be limited to eight characters, followed by a three-character file extension. This format was designed to ensure compatibility across different operating systems and devices, particularly in the early days of computing. The 8.3 naming convention is still relevant today, especially in certain environments like Windows operating systems, where legacy support is necessary. While modern systems allow longer filenames, understanding ISO 8.3 helps in managing files that may need to interact with older software or hardware.