One of the most closely held, limited circulation documents in the State Department these days is a weekly report known to those who write and read it as The PITS.

As one government official involved in its production put it. The PITS report "isn't secret or nonsecret," it's just one of those inside documents that insiders don't like to talk to outsiders about.

PITS stands for Panama Information Track Score.Complete with a chatty column of "weekly highlights" and "box scores," it is a weekly, onepage compendium of the Carter administration's efforts to inform the public of the truth about the new Panama Canal treaties.

Those efforts include, by last week's PITS count, a total of 864 scheduled appearances -- 476 live speeches or debates with treaty opponents and 388 media interviews -- by pro-treaty speakers around the country.

Since the administration's version of the truth holds the treaties to be just, wise, and in the national interest, a number of treaty opponents have questioned whether the information efforts might be construed as protreaty lobbying.

A 1926 criminal statute prohibits the use of appropriated money to pay for any effort designed to influence members of Congress to favor or oppose legislation before them. The treaties are now before the Senate, which must ratify them before they can go into effect.

White House officials maintain they are just as aware of the statute -- and other applicable prohibitions -- as are treaty opponents. They say they have been very careful about observing the often thin line between lobbying and informing.

According to one member of the White House counsel's staff, however, it would be difficult to determine in advance what violates the anti-lobbying law. Its wording is somewhat vague and there are few judicial precedents to go by -- only two cases in its 52 years of existence.

"We have throughout erred on the side of caution," said one White House official. "We have been fairly circumspect in our efforts, and have fallen far short of the limits, because we didn't even want to give the opposition the excuse of saying we used undue influence."

Instead, administration officials involved in the effort refer to their "responsibility" to participate in the national treaties debate.

"We don't pretend to be neutral," one State Department official said. "We are out saying why the treaties are good." But the speakers, he said, are careful never to urge their audiences to write their senators in favor of the treaties.

"We don't tell them to get out their pen and paper," he said. In the course of disseminating information, the speakers discuss the Senate ratification process. Anyone who subsequently wants to write his senator about what he's heard, the official said, makes his own decision.

The success of their information efforts, he said, can be judged by current national polls on the treaties. The polls show an increasingly rapid turnaround from near total rejection, at their signing last September, toward approval of the treaties.

President Carter has conducted his own information effort, with a nationally televised fireside chat on the treaties and speeches and informal briefings of at least 25 citizens' groups.

But most of the effort has been made outside Washington, where what the State Department calls its "stable" of PITS speakers has addressed groups ranging from senior citizens in Miami, to the Arizona state legislature, to the Boy Scouts of America in Doylestown, Pa.

One of the thoroughbreds in that stable, which includes Terence Todman, Assistant Secretary for Latin American Affairs, and treaty negotiator Ellsworth Bunker, as well as more than a dozen lesser known officials, is Ambassador Gale McGee, the U.S. representative to the Organization of American States.

Since the treaties were signed, MCGee has made more than 100 appearances in 22 states, from the Deep South to the Far West.

On one day last week, McGee was called away from his OAS duties twice, on 15 minutes' notice, to defend the treaties at the American Legion convention, and to talk about them on nationwide radio. "I am a volunteer pigeon," McGee said, "Ready to be sacrificed out where the bombardiers are at work."

The bombardiers are treaty opponnents, including conservative senators and political interest groups who have conducted a multimillion-dollar media and mail campaign criticizing the canal accords.

According to a White House official, the battle plan for gaining treaty ratification was drawn up last spring by presidential assistant Hamilton Jordan. "We anticipated the kinds of dynamics that would come into play," the official said, predicting that "the opposition would conduct massive letter-writing campaigns saying this was a retreat for the country."

Operating on the assumption that "they are good treaties, and the more people knew about them, the more they would support them," he said, the administration "recognized that a program of public information was our strongest suit."

That program's headquarters is in a part of the State Department's Latin America bureau called the Office of Policy. Public Affairs and Congressional Relations. As the nerve center for speaker scheduling and publication office for the PITS report, the policy and public affairs office is a splinter off State's Latin American public information department.

Nearly a year after initial strategy sessions, the office's walls resemble a Pentagon war room, filled with charts and pinboards for every state. Two full-time staff members and various staffers on a part-time basis handle treaty information.

Long before the stable of speakers was assembled, the policy and public affairs office studied its market. Last spring, when few senators had voiced a stand on the treaties, the office studied the voiting patterns of Senators on "realated types of issues" such as a several-year-old vote on Rhodesian chrome imports that would indicate a senatorial stand on moral versus national-security issues.

Newspaper editorial stands around the country were studied, along with the level of public interest in Latin America. Media markets were analyzed to determine the best way to disseminate information in various states, particularly those of senators the analysts predicted would remain undecided until the very end.

The State Department office then put together six basic presentation speeches on treaty issues, including military security, commerce and business. Latin American relations, and "myths and realities" about the treaties and Panama itself.

In addition to Todman, Bunker, McGee and other prominent officials, the office gathered more than a dozen "good presenters," primarily out of the Latin American bureau, and brought them in for treaty seminars in September and November.

The two-day seminars included talks by professional psychologists on how to relate to various kinds of audiences, and test performances on video tape. Potential speakers were given several minutes on camera to defend the treaties in front of simulated hostile audiences.

Some failed the test. "Sometimes you get good writers, good negotiators," the State Department official said. that "turn out to be bad speakers. You put them before a group, and they have the personalities of goats."

The State Department puts the total cost of the program, primarily for speaker transportation and lodging, at $39,000 so far -- more than half of which it says has been paid by the audience groups requesting speakers.

Officials said requests have been pouring in, and the speakers have no trouble finding forums. While the Panama issue is not forced on anyone, one State official said, any group that asks for a speaker on an unspecified subject "gets Panama."

The program has worked so well, a White House official said, that thought has been given to trying it on other issues.