#!/usr/bin/perl
use strict;
use warnings;

my %skip;
my $file = shift;
open(my $list, '<', $file) or die;
while(<$list>)
{
  chomp;
  next if /^$/; #skip blank lines in hash file
  #assumes that hash file is just the ID, without umPORN prefix
  $skip{ $_ }=1;
}
close($list);
{
  local($/)="";
  while (<DATA>)
  {
    next if ( m/ PORNUM: \s+ (.*) $ /mx && $skip{ $1 } );
    print "-$_-";
  }
}
__DATA__

random lines of data
PORNUM: PC21x21!2
random lines of data

random lines of data
random lines of data
PORNUM: PP22x43@.5
random lines of data

PORNUM: PP12x60@1
random lines of data
random lines of data

random lines of data
PORNUM: PC12x120/25