Vertical banner

[donkey]

Hi
I have just noticed a vertical banner running down the right hand side of some threads. It contains a zero and above that an upward pointing arrow. I clicked on one of the arrows and a message briefly appeared, I was not quick enough to read it.
Any pointers as to what it is please?

Geoff

 

[DBK]

It's about voting for posts. I think the idea is if you like the answer to a question you can vote for it. I haven't noticed it before so I suspect it isn't widely used.

Here's an example, note the Sort by date/Sort by vote buttons.