If you are mixing Hash and array refs in the variable, you need to handle each separately:

use strict;
use warnings;

my $ref = [ [ { 'BERICHT' => 'test', 'IP' => '127.0.0.1', 'NAAM' => 't
+est' },
              { 'BERICHT' => 'test', 'IP' => '127.0.0.1', 'NAAM' => 'H
+tbaa' } 
            ],
            { 'rm' => 'start', 'dummy' => '' } 
          ];


foreach my $outer (@$ref) {    
    if (ref($outer) eq "HASH"){
    print "<b>$outer->{rm}</b></br>\n";
    }else{
       print "<b>". $_->{'NAAM'} . "</b><br>\n" for @$outer; 
    }
}
[download]

Output:

<b>test</b><br>
<b>Htbaa</b><br>
<b>start</b></br>
[download]

Oops - looks like grep++ beat me to showing you how.