use Tie::DATA(':ini', 'proc_kv');

    foreach(keys %DATA)
    {
        print "$_ = $DATA{$_}\n";
    }

    # our processing function, checks for 
    # and removes processing hints in our keys
    # (see __DATA__)
    sub proc_kv
    {
        my ($k, $v) = @_;

        if($k =~ /:/)
        {
            my ($tag, $hint) = split(/:/, $k);
            $k = $tag;

            if($hint eq 'nowhitespace')
            {
                $v = ...
            }
            else
            {
                $v = ...
            }
        }

        return($k,$v);
    }

    __DATA__
    
    [foo:nowhitespace]
    yadda yadda yadda...
    
    [bar]
    ee-aye ee-aye oh

    [baz]
    woof woof