What do you look for in a con's vid-show call for vids?

[synecdochic]

I'm on the vid committee for a con this year, and we'll soon be writing our "please submit your vids to the vid show selection committee!" announcement. I volunteered to write that announcement, and since I haven't done this before, I thought it would be a good idea to ask vidders what they want to see in a call for vids.

So: What sort of thing do you look for in a con's call-for-vids announcement? What helps you feel confident that you know what the con is looking for and makes you feel comfortable submitting to it?