I often joke with friends — well, half joke — that phone calls are rude. Not all phone calls, of course, but those that come without any warning.

I’m a person who loved getting phone calls when I was younger, but growing up means getting busier. It means filling up one’s day with responsibilities, meetings, work, exercise, chatting with a loved one, or whatever else. I don’t pretend to be busier than the next person, but we all have things to do.

In this context, phone calls are just plain rude. Think about it — we don’t show up at people’s houses unannounced, because we don’t know if now is convenient for them. Unless it’s a close friend or relative, people would usually schedule a visit in advance. Right?

A cold call is the equivalent of the person showing up and banging on your front door without warning. Now, imagine you just settled into a bath when the doorbell rings. Or maybe you’re reading a story to your kids, watching a movie, or just learned a relative passed away. Or, imagine you are sitting in a formal meeting at work, and a buddy bursts in because he wants to talk to you right now. We would never tolerate these things, because they are disrespectful; at least, I couldn’t imagine doing that to somebody else.

In an age of ubiquitous mobile phones and practically free text messages, why not a quick note first? It’s just a nice thing to do, isn’t it?

Thankfully it seems most people have embraced the pre-call text message, at least in my own small circle. But if you’re still dealing with friends dialing you up without warning, designer Dan Mall might have a solution. He’s created an iPhone mockup that gives users a heads-up about the nature of a call before they answer.

From 9to5Mac:

In his concept, Dan imagines that could be a “new interim screen before the call starts that prompts you to add a subject for the call.” In his case, he’s calling someone about “Visiting Westview this weekend.” Not only is it a pretty cool idea, but would also save us time when someone calls you about “that talk.”

On the receiving end, Dan notes, the person can preview the subject of the call to decide whether or not they want to take the call right now.

It wouldn’t necessarily end unannounced calls, but at least the receiver could determine whether to answer or not. It’s a step in the right direction.

As nice as the idea sounds, though, I give it about zero chance of ever happening. If cold callers can’t be bothered to message first, it’s unlikely they’ll take the time to fill out a subject field.