#!/usr/bin/perl
# vi:ts=4 sw=4 et:
use strict;
use warnings;

#http://board.perl-community.de/thread/12073/#MSG7

#> global variables
#> ----------------------------------------------------------------------------

my $last_num = undef;

#> main script
#> ----------------------------------------------------------------------------

while ( my $line = <DATA> ) {

    chomp $line;

    if ( $line =~ m{^\s*$} ) {

        print "--8<--\n";
        next;
    }

    my ( $code, $num, $name ) = split /\|/, $line;

    if ( defined $last_num ) {

        if ( $code ne '01' and $num ne $last_num ) {

            printf "%s|%s|%s\n", $code, $num, $name;
        }
    }

    $last_num = $num;

}

#> sub routines
#> ----------------------------------------------------------------------------

__DATA__
20|2-114-560|Mayer
01|2-114-560|Mayer

01|2-010-708|Huber
01|2-011-044|Bauer

10|2-147-169|Mayer
20|2-147-554|Bauer
01|2-147-695|Huber

10|2-147-169|Mayer
20|2-147-554|Bauer
30|2-148-554|Muster
01|2-147-695|Huber