% The next line is the Revision Control System Archive Id: do not delete it. % $Id$
RCS is a public domain version control system available on both MS-DOS and Unix. By including this line, you ensure that a record will be kept within the file in the event that the file is ever maintained under RCS. That record will look something like this:
% $Id: estonia1.dtr 2.09 94/09/04 13:02:27 geraldg Exp $
and appear as the last line of the file, in place of % $Id$. It is anticipated that the Sussex archive of dtr files will be maintained under RCS.