Know what this is? Of course you don't, why would you? You don't have any need for a punctuation mark to indicate sarcasm! Why, you're never sarcastic anyway, and if you were, you'd be sufficiently obvious about it that no explicit mark would be necessary.
And if you somehow did need such a mark, you would definitely license it from Sarc Mark © software, there's no way you would just use it, right? Right. Because we all know something as subtle and complicated as a punctuation mark must have been invented, and is hence copyright-able.
Honestly, this defies parody. You would think this came from the Onion, right?