I offer this short list of definitions because it is impossible to hold a meaningful conversation or to discuss anything without the parties agreeing on the meanings of all terms in advance. Yet I see exactly this commonly happening in JFK research—few writers or speakers define their terms. There would be no problem if the terms were straightforward, but such is not the case here. For example, several important terms either have various shades of meaning or are used differently by different people. Conversely, there are cases where multiple terms mean nearly the same thing. And some terms, like "conspiracy theory," have a well-established meaning outside JFK research but are used differently here. All this can confuse even veterans in the field.

Buff—short for "assassination buff." The dictionary meaning of "buff" is "fan" or "enthusiast." Many JFK researchers dislike being called buffs because they feel that paints them in an amateurish light and diminishes the sense of dedication that many bring to their work, and it probably does. They prefer to be called "critics" or "researchers."

CE399—The nearly whole bullet found after it rolled off a stretcher in a hallway of Parkland Memorial Hospital. Although portrayed by many as pristine, it was deformed both laterally and longitudinally, to the point that some of the lead core was squeezed out of the bottom, much like toothpaste out of a tube. The bullet was traced by the ballistic engravings back to Oswald's rifle to the exclusion of all other rifles.

Conspiracist—Someone who believes that a conspiracy explains a set of evidence, as in the JFK assassination.

Conspiracy—The act of two or more people planning a crime together. The crime need not necessarily be committed in order for there to have been a conspiracy. Literally means breathing together.

Conspiracy theorist—Someone who sees events of the world in terms of conspiracies. This is a very general definition. The JFK field erroneously uses it to mean someone who proposes a specific conspiracy in the assassination. It is sometimes also used to mean someone who believe that a conspiracy killed JFK, regardless of whether the person knows the specific conspiracy. This use is identical to JFK conspiracist.

Conspiracy theory—The field of knowledge that sees events of the world in terms of conspiracies. The JFK field erroneously uses it to mean a specific conspiracy behind the assassination.

Conspirator—A party to a conspiracy.

Conspiratorialist—A term used by some to mean conspiracist.

Critic—Someone who criticizes the official investigations into the JFK assassination, usually limited to the Warren Commission and the HSCA. A critic need not be a conspiracist or even propose a specific conspiracy. To fit the definition, it is only necessary to note areas in which the official investigations were allegedly wrong. Many noncritics feel that criticism alone is not enough to prove anything, believing that without the right explanation you can't say that any other one is wrong.

CT, CTer—Abbreviations for conspiracy theorist.

Dealey Plaza—The triangular park in west Dallas where JFK was killed.

EOP—The external occipital protuberance, a small bony feature in the lower back of the head that was used by the autopsists as a reference point for the entry wound from the rear, which they said was just above the EOP and about an inch to its right. The HSCA later claimed that the bullet entered inches higher.

HSCA—The House Select Committee on Assassination, which in the late 1970s considered both the assassinations of JFK and Martin Luther King, Jr. It is perhaps best known for its finding of probable conspiracy based on its acoustic evidence, which has now been debunked.

LG—Lone gunman.

LN—Lone nutter, commonly used as an antonym for conspiracist, as in "the lone-nut view of the assassination." It is inexact, however, because a lone assassin need not automatically be a nut. It should be replaced by the more precise "nonconspiracist," or better, "lone assassin." A derivative, "LNer," is often used by conspiracists as a mildly derogatory substitute for "nonconspiracist."

MC—Mannlicher-Carcano, the type of rifle owned by Lee Harvey Oswald and used to fire bullets from the TSBD.

Nonconspiracist—Used most widely to mean someone who feels that JFK was not killed by a conspiracy. Strictly speaking, however, it means the opposite of conspiracist, or someone who feels that the evidence does not show that JFK was killed by a conspiracy. In this sense, it resembles the legal "not guilty" by referring more to lack of evidence than to a conclusion. Thus a true nonconspiracist leaves the door open for either conspiracy or a lone assassin, depending on future evidence.

NAA—Neutron activation analysis, an analytical technique in which a sample is bombarded with neutrons, usually in a nuclear reactor. Some of the neutrons are absorbed by the nuclei of the atoms in the sample, and a fraction of these atoms become artificially radioactive. From the energies and half-lives of the gamma radiation emitted, the concentrations of elements in the sample can be determined. Neutron activation is a valuable technique because it is subject to relatively few interferences and is extremely sensitive for many elements. It was used twice to analyze fragments of lead from the JFK assassination.

OES—Optical emission spectroscopy. A 1950s analytical technique that was first applied to the bullets and fragments by the FBI during the night after the assassination. Unfortunately for all concerned, the results for a series of metals in the lead and the brass were nearly meaningless because the samples were too small, the detection limits of the technique too high, and the uncertainties too large. The FBI chose not to release the results for fear that the public would misinterpret the results. That is exactly what happened, most notably by Harold Weisberg and George Michael Evica.

SBT—The single-bullet theory, which is the idea that the body wounds to Kennedy and Connally where caused by the same bullet passing through them around frame 234. This is perhaps the most contentious issue of the entire assassination, largely because it seemed to many to have been fabricated by WC investigators in a desperate attempt to save their lone-assassin explanation. The truth is quite otherwise, however, as explained by Arlen Specter and others. It was a natural outgrowth of the number of shots and shells and their timing. While not proven conclusively, it remains the only reasonable explanation for the evidence.

TSBD—The Texas School Book Depository, where Lee Harvey Oswald worked and from where all the validated shots were fired (from his rifle, by the way). All other proposed locations for shots or shooters have proven to be ephemeral.

WC—The Warren Commission, which was the first official investigation of the assassination. Formed by President Johnson a few days after the assassination, it worked during 1964 and that fall submitted a summary report and 26 supporting volumes of testimony and exhibits. It is generally recognized that the Warren Commission was the definitive study of the assassination. Even though it got a few peripheral matters wrong, it got far more right, including the basic explanation, which as survived every challenge put to it over nearly 40 years.

WCR—The Warren Commission Report.

Z film—The Zapruder film, which is the definitive visual record of the assassination shot by Dallas dressmaker Abraham Zapruder from a pedestal on the north side of Dealey Plaza, near the grassy knoll.