VFAT

VFAT long file names (also known as VFAT, LFN, FAT Long Directory Entries, etc.) is an extension of members of the FAT filesystem family (FAT12, FAT16, and FAT32) to support extended filenames. The name VFAT is derived from Virtual FAT.

Instead of just the old-style "8.3" all-uppercase filenames, VFAT filenames support Unicode, mixed case, and can be as long as 255 UCS-2 codepoints.

VFAT was introduced with Windows 95. It is the subject of several patents filed by Microsoft in the 1990s.

Format details
VFAT is a hack that works by storing the extended filename in one or more extra directory entries that appear before the "real" directory entry. Most software that is not VFAT-aware will ignore the extra entries, thinking they are volume labels, and thus something that should be ignored.

Specifications

 * Refer to the FAT32 specifications.
 * Design of the FAT file system
 * https://wiki.osdev.org/FAT#Long_File_Names

Links

 * File Allocation Table