To have a private message with one of your clan mates
It'll be a great idea if we can send private messages(pm) to a specific clan mate if we have something important to tell them and you'd only want them to know.
It doesn't have to be a chat box between the two of em, but it could be a limited text like a mail. Only to send one message in 30 mins (so they don't spam)?? Yeah..
For example; sending a pm to your leader/co leader/elder if there's any advice you need or helping a Clan mate in strategizing the attacks for clan war
This will not make the clan chat box messy. It will also not confuse the clan mates.