I need to add up-right triangle in a cell.

How to do this?
I t
Found this question through Google and ran into issues, so I'll add this here despite the age of original post.
Madara's answer works in most browsers, and works anywhere outside of a table in all browsers. But as mentioned in the comments, the example doesn't work in Firefox.
There's a very old ticket in Bugzilla concerning The main solution is to add an inner HTML: CSS: jsFiddle example I did find that it was possible to achieve without an inner position:absolute; not working in elements.
No Triangle!
td .note {
padding: 20px;
}
was empty, which probably doesn't help.