For 20 years, Jack Austin worked as an agent for College Life Insurance Co. When he finally moved on to another firm, he took with him a set of printed cards containing information about the customers to whom he had sold College Life policies. In the new job, he began reviewing those cards, and, perhaps not surprisingly, decided that most of his customers would be better off switching to Bankers Life, his new employer. College Life sued to stop Austin from using the information on the customer cards, but lost at both the trial level and, last summer, at the Indiana Court of Appeals.

The Austin case will never find a place in the law journals or legal textbooks: It is a relatively routine run-of-the-mill piece of litigation. But that is what makes it of interest to lay people, for the question of what business information belongs to you -- and thus can be carried to a new job -- and what belongs to the company that you work for is an issue of increasing contention between employers and employes.

Robert A. Spanner, a Palo Alto, Calif., attorney who is an expert on trade-secret law, says that while sexy stories of scientists taking state-of-the-art know-how from one hi-tech firm to another may capture the imagination of the press and public, by far the most common charge in trade-secret litigation is that a departing employe stole the customer list.

Jack Austin won his battle with College Life because the appellate court reasoned that the information on the cards could have been culled from other sources, including the policies themselves or calls to Austin's customers. That means that they are not really secrets, the court ruled, and so the Uniform Trade Secrets Act does not bar them from being carried off and used for another company. And College Life's other argument -- that Austin broke a covenant in his employment contract by going to work for a competitor -- also was rejected by the court. The reason: The judges decided it would be bad public policy to enforce the employment bar because it was so broad; with no limits either on time or geographic area, the contract provision, in effect, would have forbidden Austin ever to work again anywhere as an insurance salesman.

But the law on trade secrets is so confused that the Austin victory is not a green light for other employes to carry off similar information. Only six other states have joined Indiana in adopting the Uniform Trade Secrets Act, and in other jurisdictions the fact that information can be procured elsewhere does not keep it from being treated as a protectable piece of intellectual property. Some judges have held that the labor involved in compiling the data from available sources is enough to turn such customer lists into trade secrets.

In fact, the main theme of "Who Owns Innovation?," a book by Spanner that is just beginning to show up in stores, is that the law in this area is in disarray. "Cases are in hopeless conflict with one another, and an absence of well-defined and consistently applied rules of decision exists," he writes. As a result, Spanner advises caution.

Companies that want to protect trade secrets had better be very specific about which ones are really precious. A contract with Austin that had specifically forbidden him from taking policy-holder information cards to the new job might well have been enforced by the Indiana courts; the insurance company weakened its case by trying to bar too much.

But the other side of the uncertainty is that an employe leaving for a new job may get in trouble doing something that a friend in another state did with impunity. Spanner advises bending over backward to avoid breaking the fiduciary duty that the common law says all workers owe the concern for which they work. "There is a very human tendency to want to reduce the risks of a new venture by investigating the potential for business from existing customers and clients," Spanner admits. But, he warns, "these inclinations should be resolutely resisted." It's okay to tell customers that you will be leaving for a new job, but that is the only communication that is sure not to cause legal troubles. Even the statement that you will be calling back from the new position to solicit business has been held to be so unfair to the old employer that a court has barred doing further business with the customers.

The safest course is the one employes are least likely to follow: leaving for an entirely new line of business, or quitting first and then, when no longer on a payroll, beginning to look for a new job. If employes were to weigh the pocketbook risks of either of those alternatives against the chances of litigating a case claiming that by walking off with a list of customers, they had stolen trade secrets, most probably would pocket the account names. But, keep in mind, it is wise also to have at hand the name of a good lawyer.