Can posts be set to empty?

Thank you.

Well, I want to create a forum where people post short questions only. That’s why I only want people to just type their question in the title.

But then other people can come and answer by replying, just like a normal forum.

So, I would like to hide the content box just for when posting a new topic, but not for when replying. Would this be possible?

I hope you get what I mean.