What is a standard symbols for "more info" or "expand to show more"?

Question

We have a screen with a list of items. Each row (item) can be expanded to show more info.

We were planning to use a down arrow but that is counterintuitive for the items at the bottom b/c they expand UP not down (no room to expand down).

Alternatives I've considered:

• +
• ...
• > (but I worry that looks like "next")

Answer 1

I don't think there is any ISO on that, so the best I can do is share what I usually use:

Some details:

1. Drop down functionality signifier
2. Expand folder in OS X, kind of bulky, my favorite
3. Sorted column indicator, has to differ from (1)
4. Google's expand all emails icon, inverted, easily confused with download
5. A common icon for Add or Create
6. Expand folder in Windows' tree component

So I'd suggest choosing between 2 and 6, but it all depends on the context.

EDIT

Also, if you want to get your hands dirty here are Seven Ways To Test The Effectiveness Of Icons