What are the HTML entities for up and down triangles?

A little but late, but you can use ▾ ▾, and ▴ ▴, to make both the up and down filled in triangles. I was looking for it myself and the alt codes didn't help so I decided to share this. This same thing works for both left and right as well.

All named HTML entities are specified in chapter 24 of the HTML standard. The only thing missing from the page are rendered entities, but you can easily create your own copy with the additional information by applying a simple regexp:

s/<!ENTITY (\S+)/<!ENTITY \1 &\1;/

Not all entities are named. For many, you need to specify the Unicode code page, either in decimal (▲ ▲, ▼ ▼) or hex (▲ ▲, ▼ ▼).

I don't know if I've ever seen what you're looking for. Maybe a better way of doing it would be to create the arrows in Photoshop on a transparent background (.gif or .png format), and then load up the images.

Check that, you can do it through alt characters.
http://www.tedmontgomery.com/tutorial/ALTchrc.html

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