deliminator

( /de·lim'·in·ay·t@r/, n.)

   [portmanteau,  delimiter  +  eliminate]  A  string or pattern used to
   delimit  text  into  fields,  but which is itself eliminated from the
   resulting  list of fields. This jargon seems to have originated among
   Perl  hackers  in connection with the Perl split() function; however,
   it  has  been  sighted  in  live use among Java and even Visual Basic
   programmers.

[glossary]