proper nesting

I want to make sure I have this nesting correct.  It looks OK to me, but  
I've been wrong at least once before.

Comments are added here only, they are not in the real procmailrc

:0
* ^X-header: PASSED     # if they have passed the spam-checking
{

        # do some more pre-filing
        INCLUDERC=$RCFILES/formail.rc   
        
        # if they got through the prefiling WITHOUT
        # getting a 'X-Prefiled:' header, then include
        # one more RC file
        
        :0
        * ! ^X-Prefiled:
        { INCLUDERC=$RCFILES/mailer.rc }

}

Does that look right?

TjL