If you're going to break the rules, might as well break them all . . . . :)

My take has always been that using this makes it clear when abnormal termination is the main point (i.e. I expect this condition to be true, so take notice that we can terminate the program at this line).

I understand why PBP and perlstyle recommend against it; however as I said I'm partial to it. Take it or leave it as you may.