backreference

   1.  In  a  regular  expression  or  pattern match, the text which was
   matched within grouping parentheses

   2. The part of the pattern which refers back to the matched text.

   3.  By  extension,  anything which refers back to something which has
   been  seen  or  discussed  before. "When you said `she' just now, who
   were you backreferencing?"

[glossary]
[Reference(s) to this entry by made by: {Fred Foobar}]