ASCII stands for American Standard Code for Information Exchange. Except, from what I've read, they're not very standard.Here's a link to a page showing some of them:
http://www.bbsinc.com/symbol.html Here's the catch, though. They work differently, depending on what browser and operating system you are using. On that page, you'll see three headings: #, symbol, and html code. To type one of symbols, hold down your Alt key (next to your spacebar) type zero, then the # of the symbol. Example: the upside down ? is 191, so I hold down the Alt key, type 0191, then release the Alt key and, voila! ¿ !!(At least on my system). Nicko, hope I haven't opened the box on this one, but we can type Provençal correctly, now!
¿¿¿ (or, how to use ascii codes) 
