UDF

from The Free On-line Dictionary of Computing (8 July 2008)

Universal Disk Format
UDF

   <storage, standard> (UDF) A {CD-ROM} {file system} {standard}
   that is required for {DVD ROMs}.  UDF is the {OSTA}'s
   replacement for the {ISO 9660} file system used on CD-ROMs,
   but will be mostly used on DVD.  {DVD multimedia} disks use
   UDF to contain {MPEG} {audio} and {video} {streams}.

   To read DVDs you need a DVD drive, the {kernel} driver for the
   drive, MPEG video support, and a UDF driver.  DVDs containing
   both UDF filesystems and ISO 9660 filesystems can be read
   without UDF support.

   UDF can also be used by {CD-R} and {CD-RW} recorders in
   {packet writing} mode.

   (1999-09-01)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

UDF
       User Defined Function

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

UDF
       Universal Disc Format (CD, OSTA)