YA-

from The Collaborative International Dictionary of English v.0.48

Ya \Ya\ (y[aum]), adv.
   Yea. [Obs.] --Chaucer.
   [1913 Webster]

from Jargon File (4.4.4, 14 Aug 2003)

YA-
 abbrev.

   [Yet Another] In hackish acronyms this almost invariably expands to
   {Yet Another}, following the precedent set by Unix yacc(1) (Yet
   Another Compiler-Compiler). See {YABA}.

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

Yet Another
YA-

   <jargon> (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)