what should you put on a CEO’s business card?

A colleague texted me this evening to say, "Hey there. Is there a standard for CEO business cards? Do they usually include a phone # or just an email address??"

This was, at face value, a simple question. But, there is actually a lot to unpack there, because what they were really asking was how much access should folks have to our new CEO? 

And if we dig a little deeper, what we're really asking is what is the role of a CEO and where should they be putting their limited time and emotional energy? And, who gets that time and energy? 

The answer depends a lot on company culture, company size, industry, and other things. But ultimately what a CEO does is drive the long- and short-term strategy of their organization, drive the mission, and inspire their team to achieve the vision of the organization. Those things are hard, and they require a lot of focus, focus which shouldn't be interrupted by extraneous, unhelpful stuff. 

So, if you're the CEO, who are you giving your time and emotional energy to? And, why?