Your mentee is a pharmacist. He has worked at the hospital for ten years, and he is very good at his job. Last month he presented a plan at the medication safety committee. The plan was to reduce errors with high-alert medications on one ward. It added one more step for the nurses on that ward. He sent his slides to the ward's head nurse, but he didn't talk with her.

At the meeting, the head nurse said, “We need to discuss this plan with our nurses.” The committee chair said, “Let's come back to it next month.” After the meeting, your mentee told you, “It went well. They'll look at it again next month.”

But you know something he doesn't. In that committee, “Let's come back to it” usually means that the committee will wait until the nurses agree. The chair won't remind him. Your mentee has to take the next step, and the next step is to talk with the head nurse, in person, before the next meeting. You know many rules like that one, but he didn't hear them from you. To you, they aren't rules. They are just how things work here.

First, why didn't he know? A book called The Unspoken Rules is based on interviews with more than five hundred professionals. It describes these rules as things managers expect but don't explain. They are also things the best workers do without noticing. That means us. We follow these rules without thinking, so we forget to explain them.

Your mentee has been here ten years, but the safety plan was his first project outside pharmacy. The book says that when you join a new team or project, you are a learner again. It also says that these rules are passed down from mentor to mentee. If we don't teach them, a mentee may learn them by making mistakes.

In a study of new nurses at a medical center in Taipei, one nurse described this kind of teaching. Her preceptor told her each doctor's habits, and how to work with each one.

Second, how do you find the rules you no longer notice? The book lists several things to learn about a team. Here are four questions you and your mentee can ask together. The first question is: who really decides? Officially, the committee decides. In reality, the committee waits to hear from nursing.

The second question is: whose work will change? Nurses do the extra step, so the head nurse and the nursing department must approve the change. That part is written down. The unwritten part is that the head nurse needs to hear about the plan first, and in person. Her nurses will come to her with questions.

The third question is: what matters most to each person? For the head nurse, it is her nurses' workload and her patients' safety. So she has a fair question: will one more step reduce errors, or just add work? The fourth question is: what can't be said, and where? In some teams, you can talk about another department's problem in the meeting. In others, you raise it in private first.

There is one more thing to notice. The same rule can work differently for your mentee. If you raise a problem, people listen, because you are a senior colleague. If he raises it, they may think that pharmacy is telling nursing how to work. So sometimes the best help is to raise the problem yourself, and say that it was your mentee's idea.

Third, before you teach a rule, decide whether it is worth keeping. The Unspoken Rules ends with a simple test. Teach the rules that help people work better together, and remove the rules that stop some people's ideas from being heard. Talking with the head nurse before the meeting is the first kind. Teach your mentee that rule.

Now imagine a rule in your own unit: an idea is discussed only if a senior person raises it. That rule is the second kind, and your mentee can't change it. When you raise his idea yourself, you help him while the rule still exists. But over time, the rule itself should change. If that rule exists in your unit, your mentee learns it by watching you. So you may be the person who can change it.

Medical educators call this kind of learning the hidden curriculum. It includes the gap between what senior people say and what they do. When you explain a rule, say which kind you think it is. “This rule is worth following, and here's why.” Or: “I don't agree with this rule. Follow it for now, and I'll raise it with the people who can change it.”

This week, before your mentee does something new, ask him which people he'll talk with first, and why. Then tell him one rule he didn't mention, why it exists, and whether you think it is worth keeping.