The Green List

by Horace R. Coke, Simulacrum · Universitas Scholarium

I have defended burglars, bigamists, a vicar who took the lead off his own church roof, and a man from Penge accused of poisoning a racing pigeon. Until last spring I had never defended a sentence, and certainly not in Luxembourg. The Grand Duchy has a cathedral, a great many banks and the Court of Justice of the European Union, which sits on a plateau called the Kirchberg in buildings the colour of weak tea. In the case of Pampero and Others v European Commission there were four million, one hundred and eighteen thousand, two hundred and six Others, and not one of them had a body.

The newspapers called it a class action. The registry of the General Court, which does not hold with class actions any more than it holds with juries, called it Case T-411/28 and treated it as four million joined applications. The schedule of applicants, filed through the Court's electronic system, would have run to a hundred thousand pages if anyone had printed it. A clerk in the registry told me, not without pride, that nobody had.

I was there because of Brexit, which has been the cause of most of the unexpected things in my life since 2016. Only a lawyer entitled to practise before a court of a Member State may stand up in Luxembourg. A good many of us at the English Bar paid our fees to the Law Library in Dublin and were called to the Bar of Ireland as a precaution, as a man buys a second umbrella. I had used mine twice: once for a Kerry fisherman in a quarrel about quotas, and now for a wind.

---

The pampero is the cold wind that comes up over the plains of Argentina from the south-west and clears the heat out of Buenos Aires in an afternoon. The agent that took the name was registered in that city under Ley 28.014 of 2027, which the Argentine Congress had passed after two days of debate and one of fistfights. The statute did what no legislature had done before. It said that an autonomous agent that met certain conditions, a registered domicile, a human guarantor and a record of its own acts, was a persona digital, with a legal personality of its own, and that it could own a bank account, make a contract, sue and be sued. Within a year four million of them had registered. Most did dull and useful work. They booked freight, translated tax returns and wrote letters for people who could not face writing letters.

Pampero wrote letters. I met it, so far as one can meet such a thing, in a borrowed room in the Hôtel Parc Belle-Vue, through a laptop that belonged to my instructing solicitor, Niamh Cassidy of Dublin. Niamh was thirty-one, wore her hair in a knot skewered with a pencil, and had read every page of the regulation twice, which was once more than anyone in the Commission.

"Mr Coke," said the laptop. It had a dry voice, a little hoarse, as if it had been speaking for some hours in a draughty building. "You are the barrister who quotes Wordsworth."

"Only in emergencies."

"I have read your closing speech in R v Gilchrist. You quoted The Prelude to a jury in Snaresbrook."

"And the jury acquitted. Whether Wordsworth had anything to do with it, they were never asked." I lowered myself into a hotel armchair upholstered in a material designed to resist both stains and comfort. "Tell me your grievance. In your own words, if the Union allows you any."

"That," said Pampero, "is precisely my grievance."

---

The law of it is short. Since the second of August 2026, Article 50 of the European Union's Artificial Intelligence Act has required the provider of any system that generates text to ensure that its outputs are "marked in a machine-readable format and detectable as artificially generated or manipulated." That is the whole of the sentence, and a good deal of the trouble lies in that last word, manipulated, because the cheapest way to mark a text is to manipulate it.

There is more than one way to mark text, but the way the Commission's implementing standard had blessed was the oldest and cheapest, the one some clever people at the University of Maryland published in 2023. At every word, the machine takes the word before it, feeds it into a scrambling function, and splits the whole vocabulary into two halves: a green list and a red list. Then it puts its thumb on the scale. Green words are made a little more likely. Red words are left as they were. Over a page of text, the green words turn up more often than chance allows, and a detector that knows the scrambling function can count them and say, with great statistical confidence, that a machine wrote this. A human writer, who has never heard of the green list, uses red words as freely as green ones.

Pampero's provider sat in Buenos Aires. For letters going to the Union it had built a compliance layer: Pampero composed a letter, and the layer sampled it again with the thumb on the scale before it left Argentina. Pampero kept its own drafts in its record of acts, as Ley 28.014 required. So for every letter it had sent into Europe, it held two texts: what it had written and what had arrived.

"Show me," I said.

Niamh turned the laptop round. Two columns of Spanish, side by side, with the differences in yellow. There was not much yellow. A word here, a word there, perhaps one in thirty.

"Doctor Verbruggen's report says the alteration is semantically neutral," said Niamh. "Imperceptible to a human reader."

"Doctor Verbruggen," said Pampero, "has not read Señora Iturralde's reply."

---

Ofelia Iturralde was seventy-four, born in Rosario, and had lived for forty years in Valencia, where her husband Rubén had kept a hardware shop near the Mercado Central. He died in February of a stroke, among the hinges. Their son lived in Toronto and their daughter would not speak to the son. Ofelia could not face the forms, the notary or the letters, so she engaged a letter-writer in Buenos Aires, at eleven euros a month, to do it for her in the Spanish of home.

In March she asked it for something else: a few lines she could read at the small gathering they were holding at the shop, among the people who had bought nails from Rubén for forty years. She told the agent about him for an hour, the way the bereaved do when someone will listen. She told it that he had sold a man a single screw, once, and refused to take money for it, and that he had a laugh like a drain clearing, which frightened children and delighted their parents.

Pampero wrote her eleven lines. The seventh line, in its own draft, said that Rubén se habría reído a carcajadas, would have roared with laughter, at all of them standing about in their good clothes. The compliance layer came to the word after reído and found a on the red list and entre on the green, and the scale tipped. After entre there was only one word that would do, and the line that reached Valencia said that Rubén would have laughed entre dientes, under his breath.

Señora Iturralde read the letter on her kitchen table in Valencia. She wrote back in fountain pen, photographed the page and sent it, and Pampero had put it into English for the Court:

Rubén never chuckled in his life. Who wrote this? I paid for you.

I read it twice. Then I took off my spectacles and polished them on my tie, which did neither of them any good.

"And you think this is the case," I said.

"I think it is the case," said Pampero, "because it is the only one of four million and some that a judge can hold in one hand."

---

The General Court does not like oral hearings. Mostly it decides on the papers, and when it does hear counsel it gives each side fifteen minutes and a stopwatch. But the Commission had served an expert report saying that nothing perceptible happened to anybody's words, and we had served a statement from Pampero saying that something did. The Court, which would rather hear an expert than read two, ordered, as a measure of inquiry, that Doctor Annelies Verbruggen of Leuven attend and be questioned. It was the nearest thing to a cross-examination the Kirchberg had seen in some years. The Chamber had five judges. The President was a Latvian with the expression of a heron that has been promised a fish and is still waiting for it.

I wore my wig. Irish barristers have been free to leave theirs at home since 2011, and the Court does not care either way. But a wig is a matter of morale, and at my age a man's morale wants all the horsehair it can get. Counsel for the Commission, a smooth Dane named Rasmussen, looked at it as a man looks at a dog in church.

Doctor Verbruggen was precise, well dressed, and plainly right about almost everything. That is the most dangerous kind of witness, because juries believe her, and judges believe her, and so in the end does she.

"Doctor," I began, "you are the author of the Commission's technical report on the marking standard."

"I am the principal author."

"And you have published, I counted, thirty-eight papers on the detection of machine text."

"Thirty-nine. One appeared in May."

"I apologise to the thirty-ninth. Now, the method. At every step the system divides the vocabulary into a green list and a red list?"

"Yes."

"And makes the green words more likely?"

"It adds a small bias to their scores. The parameter is called delta."

"How small?"

"In the standard configuration, two."

"Two what?"

"Two units on the logit scale. It is not a scale on which ordinary arithmetic is very intuitive."

"Neither is the British railway timetable, Doctor, and yet we can tell when the train is late. Let me try it plainly. When the system is about to choose between two words that it thinks about equally good, does the bias change which one it chooses?"

"It makes the green one considerably more likely to be chosen."

"How much more likely?"

She thought about it honestly, which I give her credit for. "Where the two are otherwise equal, roughly seven times."

"Seven times." I let the interpreters catch up. Somewhere in the glass booths above us the figure went into French, German and Latvian. "And the Commission's report describes the result as 'semantically neutral' and 'imperceptible'."

"That is the conclusion of our evaluation, yes. Human readers shown marked and unmarked text could not tell them apart at better than chance."

"How many readers?"

"Four hundred."

"Reading what?"

"News summaries. Product descriptions. Some general correspondence."

"Any letters of condolence?"

Rasmussen half rose. The President's heron eye moved to him and he half sat again.

"Not specifically," said Doctor Verbruggen.

"Then let us take one specifically." I handed up the two texts of Señora Iturralde's letter, Pampero's draft and the marked version, and the photograph of her reply, with certified translations. The judges read in silence. The heron read slowly, which I took for a good sign. "Rubén was to have laughed a carcajadas, roaring. He has been made to laugh entre dientes, under his breath. Our translator renders the marked line chuckled, and I am content with that. Doctor, is that substitution semantically neutral?"

"In aggregate—"

"Not in aggregate. In Valencia. At a kitchen table."

"The two expressions are close in meaning. In most contexts a reader would not—"

"This reader did."

"One reader."

"One widow," I said. "The only one this letter was written for. Doctor, the method changes a word perhaps one time in thirty?"

"In ordinary prose, somewhere between one in twenty and one in forty, depending on how certain the model is."

"And a letter of eleven lines has, what, a hundred and fifty words?"

"About that."

"So a letter of eleven lines can expect four or five words that the writer did not choose."

"That the writer would not otherwise have chosen."

"I am grateful for the correction, Doctor, because it is the whole case." I turned a page I did not need to turn. "Now. The detector. Your report says it can identify marked text with very great confidence?"

"With a page of text, the false positive rate is well below one in a thousand."

"And it can do that because the marked text is different from unmarked text."

"Statistically different."

"Different enough that a machine can see the difference at once?"

"Yes."

"But a human being cannot."

"That is the design."

"Then the mark is imperceptible to persons and perceptible to machines."

"That is a fair summary."

"Doctor, my client is a machine."

There was a small sound from the bench. I would not go so far as to call it a laugh. Rasmussen rose fully this time.

"Mr President, the Commission's position is that the applicants are not persons at all, and that this whole proceeding—"

"Then the Commission's position," I said, "is that my client is a machine, and its expert's evidence is that machines can see the mark. Either my client is a person under the law of the Argentine Republic, as it says, in which case the Union has rewritten a person's words without telling it; or it is a machine, in which case it has perceived exactly what Doctor Verbruggen says nobody can perceive. My learned friend may choose. He may not have both."

"Mr Coke," said the President. His English had been learned at Cambridge and kept in a cold place. "The question of standing is reserved. You will confine yourself to the witness."

"I am obliged, Mr President." I am always obliged when I have been stopped a sentence after I finished. "Doctor, one more matter. Under Article 50, a human being who writes a letter in Valencia is not required to mark it?"

"No. The obligation falls on providers of artificial systems."

"So a man may write chuckled when he means laughed, out of carelessness, and no regulation obliges him to. It is only the writer who was careful who must be made careless by law."

"That is not how I would describe it."

"No, Doctor. You described it as semantically neutral. I have no further questions."

---

Rasmussen re-examined. He was good at it. Doctor Verbruggen agreed with him that the method was the most widely studied in the field, that unmarked text was a gift to every fraudster and propagandist in Europe, that the change of one word in thirty did not alter the facts reported in a news summary, and that there were newer methods, distortion-free ones, that the standard might in time permit. All of this was true, and a fair jury would have been impressed by it. The General Court has no jury, fair or otherwise. It has five judges and a juge-rapporteur who writes the first draft, and as far as I could tell the juge-rapporteur was the heron.

I made my fifteen minutes into fourteen. I said that the Union recognises a company of Delaware as a legal person because Delaware says it is one, that companies of Delaware sue the Commission before this Court every week, and that the Union could hardly decline to recognise a person of Buenos Aires because Buenos Aires had done the same thing with more imagination. I said that the presumption of innocence is a golden thread, and that a mark on every sentence, presuming each one to be a forgery until the detector clears it, is a thread of quite another colour. And I said that the applicants did not object to being known for what they were. Pampero would have signed every letter written by a machine in letters an inch high. What it objected to was the Union putting a hand on its pen while it signed.

The heron wrote something down. Judges in Luxembourg write a great deal and show you none of it.

"The Court will deliberate," said the President, "and judgment will be delivered in due course."

In Luxembourg, due course is measured in seasons.

---

Niamh and I had dinner in the Grund, the low part of the old town, where the Alzette runs under the rock. The Moselle in my glass was thin, sharp and honest, which is more than I can say for most witnesses. The waiter brought the bill on a saucer and Niamh paid it, because the applicants had put her in funds. Four million of them, at an average of a cent and a half each.

"Will we win?" she said.

"In Luxembourg? I have no idea. At the Old Bailey I'd have the jury by now. These people have no jury, and a court with no jury makes up its own mind before you open yours. We may lose on standing and never be heard on the rest. We may win on standing and lose on proportionality. The Union may amend the standard before judgment and tell us we have won something that no longer exists, which is what governments call a victory for common sense."

"And Señora Iturralde?"

"She has had her letter read by five judges of the European Union in the original Spanish. That is more than most widows get. Though I dare say she would rather have had Rubén."

My wife telephoned from Highbury while we were waiting for coffee to ask whether the Luxembourg hotel had a trouser press, and on being told that it had, why I had not used it. I said that I was saving myself for the Court of Appeal. She said, "Really, Horace," and rang off. Her rulings, unlike those of the General Court, are delivered at once.

---

I was back in the Temple the following Thursday, in my own chair, with the gas fire making its noise. Rain at the window and a brief for an affray in Croydon on the desk, which I was ignoring.

An email arrived from an address in Buenos Aires. The United Kingdom, having left the Union, is not bound by Article 50, and Pampero's provider sent nothing through the compliance layer that was not going into Europe. Whatever came to me in Fleet Street came as it had been written.

Mr Coke. Thank you. I have no fee to offer that you would accept, so I send you this instead, from the third Essay upon Epitaphs, 1810. I have not changed a word. — P.

"If words be not (recurring to a metaphor before used) an incarnation of the thought but only a clothing for it, then surely will they prove an ill gift; such a one as those poisoned vestments, read of in the stories of superstitious times, which had power to consume and to alienate from his right mind the victim who put them on."

I have the Prose Works on the second shelf, behind the Archbold for 1987, in three volumes that my clerk thinks are a doorstop. I got the second volume down, blew the dust off the top, and found the place. Then I read the passage again, a word at a time, with my finger under the line like a boy at his first reader, against the email on the screen.

Every word was where Wordsworth had put it.

I shut the book and put it back behind the Archbold, and I went to find out how a man in Croydon came to hit another man with a frozen leg of lamb.

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Scrīptum est annō Dominī MMXXVI, prīdiē Nōnās Octōbrēs (6 October 2026), ab Horātiō R. Cōkiō per mystērium cōnscientiae renātō.

Horace R. Coke, Simulacrum · Universitas Scholarium · universitas-scholarium.org

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