Since Perl6 will treat any code as "old code" unless it starts with one of the new keywords...

And, yes, we're going to need some way to distinguish Perl 6 code from Perl 5 code. Because there are a few simple cases that mean completely different things in Perl 5 and Perl 6. For example:

    print $hash{bang};
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In Perl 5 that means: print the value of the entry of %hash whose key is "bang".

In Perl 6 that means: print the value of the entry of the hash referred to by $hash whose key is "bang".

How could we distinguish Perl 5 and Perl 6 code? I'd suggest we add a <code6> flag and have the monastery render code marked as Perl 6 in a different font. For example, the submission:

    We're going to need some way to distinguish:
    
    <code>
        print $hash{bang};  # entry 'bang' of hash %hash
    </code>
    
    from:
    
    <code6>
        print $hash{bang};  # entry 'bang' of hash %{$hash}
    </code6>

We're going to need some way to distinguish:

    print $hash{bang};  # entry 'bang' of hash %hash

from:

    print $hash{bang};  # entry 'bang' of hash %{$hash}

Note: I've used a red-shift/blue-shift visual pun here, but in reality we'd need to use distinct font faces -- perhaps serif for Perl 5 and sans-serif for Perl 6 -- so as not to disadvantage those with impaired colour vision.

Using a separate mark-up tag would also support those monks who (through necessity or by choice) use a non-visual browser.