V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

UTF
       UCS Transformation Format (Unicode, UCS)


The Free On-line Dictionary of Computing (30 December 2018):

UCS transformation format
UTF

    (UTF) A set of standard character
   encodings in accordance with ISO 10646.

   One of a set of standard character encodings, the most widely
   used of which are UTF-8, UTF-16, and UTF-32.  The code tables
   in ISO 10646 and in the Unicode standard are identical,
   although the Unicode standard includes additional material.

   UTF-8 is the most widely used encoding, at least on Unix
   systems.  Since it does not include any bytes like '\0' or '/'
   which have a special meaning in filenames and other C
   library function parameters, and 7-bit ASCII characters have
   the same encoding under both ASCII and UTF-8, the required
   changes to existing software are minimised.

   Other UTFs: UTF-1 and UTF-7 are not widely used.

   UTF-8 and Unicode FAQ for Unix/Linux
   (http://cl.cam.ac.uk/~mgk25/unicode.html#ucs).

   (2002-01-15)