+1  A: 

This one seems to imply that 030 and 031 are up and down triangles.

(As bobince pointed out, this doesn't seem to be an ASCII standard)

FrustratedWithFormsDesigner
that link doesn't work.
Timj
Works for me...
37Stars
works for me. ...The link, not the characters; that's [Code page 437](http://en.wikipedia.org/wiki/Code_page_437), not ASCII at all. 437 is an old DOS code page not usable in browsers.
bobince
I just tried "ALT-[NUMPAD 3]-[NUMPAD 1]" and got: ▼(OS is Windows XP SP3, browser is Firefox 3.6(?)).
FrustratedWithFormsDesigner
@bobince: Interesting... came up in a google search for ASCII tables...
FrustratedWithFormsDesigner
A: 

No, there is not. Use an image.

Alternately, you can use UTF-8, not ASCII.

http://www.fileformat.info/info/unicode/block/geometric_shapes/utf8test.htm

▲ = ▲

Diodeus
+13  A: 

Not ASCII (neither's ↑/↓), but Unicode:

▲ - U+25B2 BLACK UP-POINTING TRIANGLE

▼ - U+25BC BLACK DOWN-POINTING TRIANGLE

▲ and ▼ if you can't include Unicode characters directly. (Use UTF-8!)

Also ▴/▾ (U+25B4, U+25BE) for ‘SMALL’ versions, though font support isn't as good so you'd probably be better off just using the large versions in smaller font.

bobince
+2  A: 

How about these?

˅ ˄

2C4 and 2C5 respectively.

Fyodor Soikin
I can't get that to work? what's the full html code? "" (without spaces)
Timj
It's hex, so `˄` or decimal `˄`. But if you've got your page encodings right you should just be able to copy-and-paste them into the doc.
bobince
A: 

▲▼ These are U+25B2 and U+25BC respectively

Ron Harlev