For all you who have wondered what in the heck ALT+255 is.....here is the answer.
www.asciitable.com/
Scroll past the incomprehensible stuff at the top, till you get to the chart labeled "Extended Ascii codes," then open a notepad file and have some fun.
What those numbers do is this: In your notepad, or whatever text file you choose, hold down the ALT key while you type in any of those numbers, and it will produce the character shown. For example, holding down the ALT key while typing 129 (this only works with the numeric keypad, not the number keys at the top of the keyboard) will produce this: üALT +
128 = Ç
133 = à
152 = ÿ
255 =
etc...
The ALT+255 joke is that it produces a blank character, in effect the same thing as hitting the spacebar. And so it really does mean, quite literally, nothing at all. The chart provided in the above link does not represent all the possibilities of ALT+......just the most standard set, I think. Try experimenting a little, see what you can find that's not on the given chart.
Here are some I discovered on my own:
alt+11 = ♂
alt+12 = ♀
alt+13 = ♪
alt+14 = ♫
alt+15 = ☼
alt+16 = ►
alt+17 = ◄
alt+18 = ↕
alt+19 = ‼
alt+20 = ¶
alt+21 = §
alt+22 = ▬
alt+23 = ↨
alt+24 = ↑
alt+25 = ↓
alt+26 = →
alt+27 = ←
alt+28 = ∟
alt+29 = ↔
Hmmm...for some reason, some of those aren't showing up correctly here. When I type ALT+14 in a notepad, I get two musical notes....
Anyway...that's what it's all about. Have some fun with it, if you're so inclined.
Hope this helps.
I have no idea there, I'm afraid.... 
