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The Origins of the Prison Tap Code

It was always an adventure to make contact with a new shoot down, no matter what prison you happened to be in. Certainly you did not wish them ill, but in a society where thought control prevailed and familial communication was minimal to non-existent, you became starved for news. And the new shoot downs were the only source of the straight skinny.

 Incoming and outgoing communications were censored. In the early years I was actually tortured to write letters home. Refusing to write because of censorship and the fact that letters were the justification for traitorous “peace groups” to conduct their treason, made such refusal a keystone of resistance posture.

 There were difficulties associated with initiating contact within the prison system since communication of any kind between prisoners was considered a sign of leadership and subversion by our jailers. New prisoners were isolated while awaiting interrogation and torture if not compliant. After processing they were as space allowed placed in solitary confinement for attitude adjustment purposes. To complicate matters further, most aviators only had a rudimentary knowledge, if any, of Morse Code.
Tap CodeMorse Code as a means of prison communication had severe limitations. There were only occasional cigarette wrappers or paper towel like toilet paper with no pencils or ink available for communication. You could manufacture ink out of brick dust and sundry such elements and use bamboo slivers for pens.

The only sure way of communicating thusly was to drop a note in an emptied toilet bucket, float a note out on you manure, hide a note at a wash trough, or scratch a message on the bottom of a rice bowl. But you had to contact the guy first to tell him all this.

The preferred, most secure and most reliable method was to tap on the walls or floor pad in a rhythmic code known to us as the Tap Code. The code in fact was a quadratic alphabet made up of twenty five letters in a box five across the top and five down the side


Since our English alphabet has 26 letters, our guys left the letter “K” out to form the symmetrical (5x5) box. (They must have been engineers, certainly not English majors.)

The mnemonic we utilized in relaying the concept with a minimum of words was:  American Football League Quits Victorious” – Tap Code – First Letters of Box. You see, if you were caught communicating the penalty was torture, public humiliation and force propaganda statements. So words had to be parsimonious; the tutorial had to be brief.

The method for using the quadratic alphabet was simple: the first tap signified the row across and the second tap signified the letter in that row. Some examples: tap (first row) tap tap tap (third letter) = C; tap tap (second row), tap tap tap (third letter), pause, tap tap (second row) tap tap tap tap (fourth letter) = HI.

To initiate communication you would tap the rhythmic five tap “shave and a hair cut” with the response being an immediate two tap (two bits). The guards never could imitate the unique rhythm of shave and a hair cut, so they couldn’t sucker us into betraying ourselves. You would terminate all conversations with “CU; GBU” (See You; God Bless You).

If you had no verbal contract with a prisoner you had to teach all this by pounding at great risk through the wall. At first a guy would think it was Morse code, as I did, and would agonize over trying to remember it and using it. But Morse was too dangerous to use by tapping, even if the guy could remember it. You would have to use a “tap” for a dot and a “thump” for a dash. If a guard didn’t catch you first, the walls would eventually fall down. Besides it would be slow and tedious at best.

The result would be that you would have to patiently and endlessly repeat the sequence which most would pick up on until you got to the letter “K”. It was not intuitively obvious why “K” should have been omitted to form the box instead of “Q”.

A series of quiet thumps would be the erase signal (one loud thump was a danger, emergency disconnect signal) and you would start over. It would take anywhere from six to sixty hours to teach the code in this manner depending on the imaginative skills or the pupil.Tap Code

We established contact with a fighter pilot who had yet to be tortured. The line was long, torture is labor intensive and most subjects were less than cooperative. We asked him what they were teaching in the prison compound phase of survival school, especially about communicating. Imagine our amazement and consternation when he reported that the instructors had mentioned that we had a “secret code” which his fellow prisoners would teach him when he arrived there. Secret? It had been public knowledge for centuries.

Various members of our group claimed to have invented the quadratic alphabet which we were using. One was a group of engineers by training. If so, they probably dropped out the “K” under the theory that “C” would double for the hard sound – like we were going to be talking the code! Others had just picked it up in the course of their living and listening experience. One guy claimed it was part of his Polish family lore in respect to trapped miners communicating with rescue parties. Another claimed that he had read of it in Reader’s Digest. I remembered prisoner communication being a leitmotif of some novel regarding a political prisoner* in a European communist prison; but could not remember the code nor remember the title until researching it after my repatriation.

Some of our members developed great facility using the code, tapping so swiftly that the listening guards were certain that we were simply harassing them and not communicating any meaningful data. Jerry Denton, capitalized on the TB like symptoms of most of our guards by developing a cough, sneeze, hock, spit, clear, honk, sniffle and choke sequence to send the Tap Code. It sort of blended in with the ambient prison background noise especially in the winter. Others took advantage of the hand held bamboo (outside) and straw (inside) brooms to sweep out the code. Others would scavenge paper and punch Tap Code holes in the paper for delivery to out of the way isolated cells. The uses of the Tap Code and its variations were limited only by human inventiveness.

Communication was the life blood of our resistance and survival. Names of prisoners had the highest priority. Then in order came instructions from our own leaders, escape plans, resistance postures, intelligence regarding the prison and our captors, themes interrogation was focusing on, Sunday prayers and news of the war. After that it was open season: jokes, education, family stories, sea stories, movies, novels, chess, etc. etc.

One of the hard line rules, and there were very few, from our prisoner leadership was: “Communicate at all costs.” Those who refused to communicate were isolated from their fellow Americans and susceptible to the blandishments of their captors. In fact, the fighter pilot dropped off line, never was threatened or tortured, gave his parole and betrayed us by violating direct orders to not accept a propaganda release. He went home early, to his everlasting shame, with a group of American peace activist traitors.

Our objective in fighting our war as prisoners was to resist to the utmost of our ability, support our fellow prisoners, deny the enemy any intelligence or propaganda advantage from our captivity, and return with honor. Communication was the key to the success that our leadership was able to inspire and to realize. We owe a lot to the Tap Code.

Richard A. Stratton
Atlantic Beach, Florida
Autumnal Equinox 2003


* Nicholas Salmanovitch Rubashov in The New Model Prison

Gradually, he became conscious of a small but persistent ticking sound in his cell. He turned round listening. The knocking was so quiet that at first he could not distinguish from which wall it came. While he was listening, it stopped.

He started tapping himself, first on the wall over the bucket, in the direction of No. 406, but got no answer. He tried the other wall which separated him from No. 402, next to his bed. Here he got answer.

Rubashov sat down comfortably on the bunk, from where he could keep an eye on the spy-hole, his heart beating. The first contact was always very exciting.

No. 402 was now tapping regularly; three times with short intervals, then a pause, then again three times. Rubashov repeated the same series to indicate that he head. He was anxious to find out whether the other knew the “quadratic alphabet”– otherwise there would be a lot of fumbling until he had taught it to him.

The wall was thick with poor resonance; he had to put his head close to it to hear clearly and at the same time he had to watch the spy-hole. No. 402 had obviously had a lot of practice; he tapped distinctly and unhurriedly, probably with some hard object such as a pencil.

While Rubashov was memorizing the numbers, he tried, being out of practice, to visualize the square of letters with the 25 compartments – five horizontal rows with five letters in each. No. 402 first tapped five times – accordingly the fifth row; W. Then a pause; then two taps – the second row, F – J; then three taps – the third letter of the row: H. Then three times and then five times; so fifth letter of the third row: O. He stopped.


By Arthur Koestler
The Macmillan Company 1941