Editing File Allocation Table (section)

=== <span id="LFN"></span><span id="VFAT"></span><span id="UVFAT"></span>Long file names ===
<!-- use LFN anchor for generic FAT long filename solutions and VFAT for Microsoft's VFAT -->

One of the [[user experience]] goals for the designers of [[Windows 95]] was the ability to use [[long filename]]s (LFNs—up to 255 [[UTF-16]] [[code unit]]s long),<ref group="nb" name="NB_LFN_UNI"/> in addition to classic [[8.3 filename]]s (SFNs). For [[backward compatibility|backward]] and [[forward compatibility]], LFNs were implemented as an optional extension on top of the existing FAT file system structures using a [[workaround]] in the way directory entries are laid out.

This transparent method to store long file names in the existing FAT file systems without altering their data structures is usually known as '''[[VFAT long filename|VFAT]]''' (for "Virtual FAT") after the Windows 95 [[VxD|virtual device driver]].<ref group="nb" name="NB_VFAT_Name" />

Non VFAT-enabled operating systems can still access the files under their short file name alias without restrictions; however, the associated long file names may be lost when files with long filenames are copied under non VFAT-aware operating systems.

In Windows&nbsp;NT, support for VFAT long filenames began with version [[Windows NT 3.5|3.5]].

Linux provides a VFAT filesystem driver to work with FAT volumes with VFAT long filenames. For some time, a [[UVFAT]] driver was available to provide combined support for [[#UMSDOS|UMSDOS]]-style permissions with VFAT long filenames.

[[OS/2]] added long filename support to FAT using [[FAT extended file attributes|extended attributes]] (EA) before the introduction of VFAT. Thus, VFAT long filenames are invisible to OS/2, and EA long filenames are invisible to Windows; therefore, experienced users of both operating systems would have to manually rename the files.

[[Human68K]] supported up to [[18.3 filename]]s and ([[Shift JIS]]) [[Kanji]] characters in a proprietary FAT file system variant.

In order to support [[Java (programming language)|Java]] applications, the [[FlexOS]]-based [[IBM 4690 OS]] version 2 introduced its own [[virtual file system]] (VFS) architecture to store long filenames in the FAT file system in a backwards-compatible fashion. If enabled, the virtual filenames (VFN) are available under separate logical drive letters, whereas the real filenames (RFN) remain available under the original drive letters.<ref name="IBM_4690_Programming_Guide" />