Marge: Well, Homer, maybe you can take some consolation in the fact that something you created is making so many people happy.
Homer: Oh, look at me! I'm making people happy! I'm the magical man from happyland in a gumdrop house on lollipop lane! By the way, I was being sarcastic!
My high school
Latin teacher had a saying: "How can you tell it's satire? Why, it's written in blue, of course!" I particularly liked it because, of course, the saying was satirical in itself.
But why not implement it?
Of course, there are several problems as it stands: first, it kind of ruins the effect of satire if you actually <i>say</i>, by whatever method, that it's a satire. I've been known to put "before you send me angry letters, keep in mind that this is a satire" in tiny text at the bottom of a satirical article, but I don't really like to do it; blue text, similarly, isn't something I'd want.
But CSS makes possible a new possibility: just enclose the text in a div or span tag (or alter the tag that it's inclosed in) of the class "satire". If this practice became fairly standard, then those who see in themselves a tendency to misinterpret satire could set their browsers to, say, display the text in blue, or give it an orange background.
(Moreover, you could use this instead of smileys; just define a "joke" class. It would work for rants, too; instead of putting </rant> at the end, put it inside a div of class "rant". (Alternately, you could define an XML tag <satire>.))
Pros: the satire is still shown without the "nudge-nudge, wink-wink" to most people; the only ones who recieve it are the ones that need it.
Cons: People would have to know that they usually miss satire. And if they knew that, they probably wouldn't miss it. Plus, a lot of browsers don't support user-defined style-sheets.
Another possiblity is to have an online database that assigns satire numbers. The database could contain about 99,000 five-digit numbers, half of which are marked in the database as "satire" and half of which are not. If you've written a satire, you would go to the site, push a button marked "satire", and get one of the "satire" 5-digit numbers (or, alternately, if you've written a non-satire, you would go to the site and get one of the "non-satire" numbers. It's possible the numbers could also be further subdivided into "rant" categories, etc.) You'd then copy and paste the number at the end of your document (or simply write it there if the document isn't on a computer). Anyone confused about whether what you wrote was a satire could go to the website and enter the number, and the website would tell them (it's likely that someone to whom the possibility of the article being a satire might have otherwise have never occured would see the number and be reminded, and decide to check). Anyone else would just see a meaningless string of digits. (On the web, the digits could be enclosed in a div of class "satire number", which could be rendered invisible for those who don't want to see it.)
Pros: Number of numbers is large enough to prevent people from remembering which ones indicate satire and non-satire; numbers serve as a reminder that it might be satire without saying for sure that it is.
Cons: Sometimes it's hard to seperate "satire" and "non-satire" into two entirely distinct spheres; eventually someone would deliberately mark a satire or semi-satire as non-satire to make a statement.