When Kim Kihwan, a South Korean trade envoy, entered the Oval Office on Oct. 2, 1985, President Reagan was ready for him.

The National Security Council staff had given Reagan a page of "talking points," suggesting what the president should say to Kim as he delivered a letter from South Korean President Chun Doo Hwan.

The notes, in their entirety, read:

"Thank you very much, Dr. Kim, for bringing this letter to me.

"I know how much President Chun has been doing to ease trade difficulties between our two countries and I appreciate that.

"Please give President Chun my warmest regards."

It isn't clear if the president actually spoke those words as he greeted the Korean trade representative in a meeting that occupied fully two minutes of Reagan's day.

But it has been details such as those that have formed the essence of the case against former White House aide Michael K. Deaver, who some feel used his friendships with Reagan administration officials to do favors for his high-paying clientele. Deaver is said to have arranged Kim's visit over the objections of Donald T. Regan, then White House chief of staff.

If "talking points" was a new governmental concept to the jury of Washington residents hearing testimony on the five counts of perjury a special prosecutor is pursuing against Deaver, it is only one of many bits of bureaucratic lingo that have become central to the complex case.

Some examples:

The subject of Nancy Reagan, a close friend of Deaver, was introduced to the jury by the code name "Foxtrot," the Secret Service code for her aircraft.

Information flows through the State Department, one of its top officials acknowledged, at two basic speeds. There is "fast paper," bulletins and news flashes, and there is the rest, cable messages and memos, known as "slow paper."

Messages from the secretary of state to the president are known as "Sec-Pres" and cables from U.S. ambassadors to the State Department about diplomatic conversations are "mem-cons." The failure of the former ambassador to South Korea, Richard L. (Dixie) Walker, to file a "mem-con" on one meeting at which he was present with Deaver and Chun raised defense doubts about portions of Walker's testimony.

Some issues have been reduced to a number. Deaver's trial, which is scheduled to enter its 16th day of testimony today, has a "936" feud as one of its central issues. And concerns about "301 cases" were critical in dealings with the Japanese.

Both draw their names from the sections of the law at issue. The 301 cases deal with U.S. charges that the Koreans were dumping certain products in American markets at unfair prices.

The 936 feud was a 1985 dispute over an unsuccessful attempt by the Treasury Department to kill special benefits for Puerto Rican manufacturers set out in Section 936 of the tax code.

As the Deaver jurors should know after 15 days of testimony, the issue arose in a Treasury document known as "T-1."

But "T-1" was soon replaced by "T-2," or as it was more formally known, "White House 1."

It hasn't all been dull. When National Security Council staff member Stephen I. Danzansky attempted to alert his boss, Rear Adm. John M. Poindexter, to efforts to resolve the dispute, he called his memo "Son of 936." Poindexter's reaction wasn't disclosed.

The importance of knowing these bureaucratic phrases cannot be underestimated. Sometimes it appears that the key to Deaver's initial success as a lobbyist was his ability to speak the bureaucratic language.

Air Force Col. Gerald M. May, another NSC staffer, recalled that Deaver called him from an airport and asked: "Can you tell me what happened at the BRB?"

May said he quickly told Deaver what he wanted to know: that a "BRB," for Budget Review Board, had reviewed and rejected a National Aeronautics and Space Administration request for more money for a space station.

But Brig. Gen. Matthew P. Caulfield, the former deputy director of the White House Military Office, told of turning aside suggestions from Deaver that the White House needed to have more of a voice in the Air Force review panels selecting a new presidential airplane.

Deaver's credibility with Caulfield may have suffered from his lack of knowledge concerning military jargon. To the dismay of prosecutors, Caulfield, a Marine Corps officer, said Deaver, the former White House deputy chief of staff, had never heard of the term "hardening" until the general mentioned it to him at a breakfast at the Four Seasons Hotel in Georgetown.

The military term refers to ways to protect communications gear from the intense electromagnetic waves generated by nuclear explosions. The fear of such damage was a crucial reason for the request for a new aircraft.

The chances for more bureaucratic talk in the trial are narrowing. Prosecutor Whitney North Seymour Jr. has called 43 of his scheduled 57 witnesses. In a petition filed Wednesday, he indicated what is likely to be the last bureaucratic term he would like U.S. District Court Judge Thomas Penfield Jackson to put before the jury.

That's Section 207(c) of the Ethics in Government Act. It restricts lobbying by former senior government officials. The prosecution and defense have clashed over whether Deaver may have violated the section. The defense says he did not and "the proof" is that he is not charged with violating the act, only with failing to recall certain contacts in congressional and grand jury testimony.

The prosecutor says that Deaver was familiar enough with the law to know that he might have violated it and that his fear of being charged prompted his false testimony.