The Jargon File (version 4.4.7, 29 Dec 2003):

Yet Another
 adj.

    [From Unix's yacc(1), ?Yet Another Compiler-Compiler?, a LALR parser
    generator]

    1. Of your own work: A humorous allusion often used in titles to
    acknowledge that the topic is not original, though the content is. As in
    ?Yet Another AI Group? or ?Yet Another Simulated Annealing Algorithm?.

    2. Of others' work: Describes something of which there are already far too
    many. See also YA-, YABA, YAUN.


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

Yet Another
YA-

    (YA-, after Unix's yacc - Yet Another
   Compiler-Compiler) A humorous allusion often used in titles to
   acknowledge that the topic is not original, though the content
   is.  As in "Yet Another AI Group" or "Yet Another Simulated
   Annealing Algorithm".  If used of others' work, it
   describes something of which there are already far too many.

   In hackish acronyms the "YA" prefix almost invariably expands
   to Yet Another, e.g. YABA, YAUN.

   [Jargon File]

   (1996-11-26)