Don’t use the phone if you want to pass on sensitive information so that the public is better informed.

That’s one of the main lessons to be learned from the spying scandal involving the board of directors of Hewlett-Packard Co.

On Sept. 6, the company acknowledged that it had conducted an investigation to determine which of its board members had been leaking information about its board meetings to the press. In the course of that probe, according to published reports, investigators hired by the company obtained telephone records by impersonating board members, employees and journalists.

There is no particular reason to believe that telephone records should be legally protected from outside eyes. They’re not like personal medical records, for instance. Still, most of us are under the impression that whom we called, or who called us, is nobody’s business and should not be disclosed to third parties.

The news stories about the HP probe make clear that telephone records are not all that hard to get. Also, we all have learned in recent years that with digital technology, nothing you do involving computers goes unrecorded. On computers handling phone traffic, there always seems to be some record that can be traced by somebody who knows how.

At the same time, in a free country it’s also important and useful for the public to learn, now and then, about matters that the participants want to keep to themselves. This goes for government as well as for corporate America. After all, corporate decisions often affect the public far more than decisions made by legislators or public agencies.

That’s where the lesson comes in, the lesson for people who believe it is their duty to pass confidential information to the press so that the public will be informed: Don’t use the phone.

Instead, make contact some other way. For example, write a note and send it through the mail. Copies of documents, too, can be sent so the source cannot be traced.

Another way: Use a phone booth — if you can still find one — and leave a message on a reporter’s phone to set up a personal meeting.

It may not be necessary to follow “Moscow rules” as described in the spy novels of John Le Carre, but then again it might not hurt. The term refers to procedures to make sure one is not followed to a meeting — including fall-backs if one is. (For details, reread “Smiley’s People.”)

If all this sounds too much like cloaks and daggers, it can’t be helped. It’s safer than using the phone. (hh)