Associate Dean for Research Administration Patrick W. Fitzgerald runs his finger across the spines of a vast collection of nondescript volumes in the top corner of his bookshelf. He settles on a slim, drab, dust-colored booklet. Nearly 14 years after the termination of its printed publication, “Principles and Policies That Govern Your Research, Instruction, and Other Professional Activities,” known colloquially as the Grey Book, makes a public appearance once again. “This is something people really don’t refer to much anymore, so I was surprised to see anybody looking into this, and I was surprised you even know about it,” Fitzgerald says.

The Grey Book is a written set of guidelines detailing the complex code of conduct expected of all professors at the University. Specifically, it outlines areas such as conflict of interest, research ethics, confidentiality, and even the amount of time that Harvard professors are allowed to spend on non-Harvard pursuits. The print version of the Grey Book was discontinued in 2002, when it was uploaded to an obscure webpage on the Faculty of Arts and Sciences website. The Research Administration Services department then fragmented this digitized copy of the Grey Book in 2014, scattering its sections across the Harvard internet database. Today, the Grey Book is almost impossible to track down in its entirety, its name lost to Harvard’s institutional history and largely unrecognized by most faculty and students.

One regulation in the Grey Book, that “no more than 20 percent of one’s total professional effort may be directed outside of work,” seems like it would pose a problem for some professors. How do Harvard’s most active professors strike a balance between their activities within and without the fine limits defined by the Grey Book?

Laurence H. Tribe, a professor at Harvard Law School, finds integrating his out-of-university judicial activities and his teaching easy. “I have not received much conflict in terms of my activities outside of the University,” he says. “I never take advantage of my title as a Harvard professor to gain the upper hand in my pursuits outside of the college.” Tribe, who has argued an impressive 35 cases before the Supreme Court and authored 115 books and scholarly journal articles, feels that Harvard never infringes upon his intellectual standpoints on most issues. He cites Harvard’s policy of “transparency,” the expectation that professors offer information on their webpages regarding their outside activities and opinions, as proof of Harvard’s leniency. “In fact,” he notes, “I consider what I teach to be a rather seamless transition with my activities outside of the college.”

N. Gregory Mankiw, an economics professor and former Chair of the Council of Economic Advisers under President George W. Bush, similarly considers the restrictions defined under the Grey Book rather relaxed. He says, “One thing I always think about is the opportunity cost. One great thing about being a professor is that you really do have a lot of autonomy.” Like Tribe, Mankiw believes that the guidelines outlined in the Grey Book are incredibly flexible. “If you’re writing a textbook, if you’re sitting in your office writing an article for The New York Times—is that a non-Harvard activity? The application of the rule is often kind of murky, and in some sense the rule is there just to give people guidance.”

Thick with chapter upon chapter of seemingly inflexible rules and regulations, the enigmatic Grey Book is perhaps not as rigid as it seems. The different editions of the Grey Book were originally intended to inform professors about new rule changes rather than enforce them. “We try not to be punitive and say, ‘No, you can’t do that,’” Fitzgerald explains. “You can do what you’d like to do, but here’s the way that will conform to the regulations and make sure that you are not jeopardizing your program.”

Mankiw agees. “You have tremendous autonomy to figure out what sort of life you want to lead,” he says. “I view myself as a representative of the university in many ways, and I think the university likes the fact that I’m doing that.”