After months of dithering and unkempt debate, the British government has announced that it will seek to commence formal divorce proceedings later this month, giving effect to the referendum in which a wispy majority of Brits voted to leave a union of which they’d been an essential (but not well-loved) part for 44 years. To mark the moment, POLITICO offers its readers a handy vocabulary to help stay on top of this Mother of all Rifts.

is for Article 50 (of the Treaty of Lisbon), which, when “triggered”— a suitably violent verb — will start the clock running on what could be a most ill-tempered political separation. Article 50 gives Britain and the EU two years to sort out their mutual severance, but with every member country having a veto over every jot and tittle, 730 days will never have looked so paltry.

is for Michel Barnier, the EU’s chief Brexit negotiator. His British counterparts regard him as the worst thing to have come out of Savoy since cabbage; but in Brussels, he is thought of as an adamant and ambitious defender of the values of EU Inc.

is for David Cameron, the gambler who lost it all. He promised a Brexit referendum in January 2013 to unite his party and see off the pesky UKIP mob; but as he’s reported to have said on the morning after the referendum, “Well, that didn’t go according to plan.” And that, in large part, was thanks to Dominic Cummings, the devilishly efficient driver of the Vote Leave campaign (and the author of some of the most long-winded blog posts in history). Cummings bet on populist emotion, entirely in keeping with his view that “rational discussion accomplishes almost nothing in politics.”

is for the British cabinet defectors who abandoned Cameron for the Brexit camp. The most prominent among them were the histrionic Boris Johnson and the cerebral Michael Gove, whose betrayal wounded Cameron grievously and electrified the Leavers with some vital political wattage.

is for “ever closer union,” words that have almost religious significance among the Brussels elite, but which, in the U.K., came to acquire all the qualities of a death threat. The phrase is found in the preamble of the EU’s founding document, and the U.K. had signed on to this principle on at least six occasions. Never mind that, though: It was an Ever Distant Union that Britain really wanted.

is for Nigel Farage, the vainglorious patron saint of Brexit and the man who did more than anyone to push Cameron into the darkest recesses of a referendum. However, contrary to his own voluble belief, the UKIP leader was not The Man Who Won It. (That accolade is shared by Cummings, Gove and Johnson.)

is for Gibraltar, that doughty British territory on the Continent, which voted to remain in the EU by a margin — 96 percent — that would make the president of Turkmenistan proud. In fact, for days after the vote, distraught Gibraltarians could talk of little else but the 823 of their compatriots who voted for Brexit. The Rock now fears for its way of life — and Madrid’s predatory intentions. (G is also for Greece, the Platonic example to British voters of the EU’s seemingly insoluble economic problems.)

is for “hard Brexit” — a phrase that would make you giggle were its implications not so desperately irrational. The British government wants to have tariff-free access to Europe’s markets without paying the sort of fee that Norway does. Brussels’ response is unprintable. Each side is, in effect, willing to take a significant cut in GDP to spite the other.

is for Ireland, which, while not as orphaned as Gibraltar, could be heading for an economic hiding. “What does the Brexit nightmare mean for Ireland?” is the sort of headline one is now accustomed to reading in the Irish press, as Dublin braces for border controls between its island’s north and south, and for the departure from the EU of its biggest export market. (I is also for ISIS: If the attacks on Paris and Brussels hadn’t occurred, would Britons have voted to leave?)

is for June 23, 2016, the date that changed the course of British history as profoundly as anything since the Battle of Hastings. And let’s not forget Jean-Claude Juncker, president of the European commission, the man whom many Brits regard as the quintessential arrogant Eurocrat. (And after Cameron’s ill-fated Stop Juncker campaign — in which he tried to block the Luxembourger from the EU’s top job — it’s unlikely Juncker will look benignly on British demands in the negotiations.)

is for Sadiq Khan, the mayor of London, whose cosmopolitan city was routed in the Brexit referendum. Khan, deeply fearful for London’s future, has conducted an impassioned campaign for an early trade deal with the EU in order to stave off “catastrophe” in the British capital. (Well over a million EU citizens currently live in London.)

is for Labour, Britain’s pre-eminent pro-European party, whose leader, Jeremy Corbyn, cost Remain a victory by his mulish refusal to campaign with Cameron. It’s fair to say that Brexit wouldn’t have happened without Labour’s political implosion. The party didn’t share its voter-registration information with the Stronger In campaign, saying “Our data is our data.” Post-referendum math revealed that Leave would have lost if a mere 600,000 voters had switched to Remain.

is for Theresa May, now British prime minister because she was the Last One Standing after the referendum. From a British perspective, she appears to have done the right thing by activating Article 50 at the latest possible stage, but critics ask if she has the heft — and the strategic vision — to win a bruising battle with Barnier & Co. One thing’s for sure: She benefits greatly from having the most incompetent opposition in modern British history.

is for nationalism, which has raised its head defiantly in many parts of Europe, but which, so far, has won its only clear political victory in Britain. Let us not forget, however, that 48.1 percent of those taking part in the Brexit referendum voted to remain in the EU — so there’s a danger of overstating the degree to which Britain has swung to the nationalist right.

is for George Osborne, Cameron’s Sancho Panza, who argued — wrongly, as it turned out — that the Remain campaign should be fought largely on an economic platform. Alongside him was Craig Oliver, No. 10’s director of communications, who, with a gaggle of bien-pensant Westminster insiders, ran the Stronger In campaign. The feeble Oliver was had for breakfast by Cummings.

is for the pollsters, who got the result so spectacularly wrong, and for parliamentary sovereignty, which asserted itself — as a civics lesson to the nation — after the referendum. The Supreme Court ruled that Article 50 could not be set in motion without an enabling act of parliament, which was duly obtained. (A note, here, in praise of the House of Lords: Whereas the House of Commons caved in to the government, the Lords — bloated, unelected, and second-rate, to quote its habitual critics — fought hard, if unsuccessfully, for amendments that would have softened some of the toughness of Brexit.)

is for the Queen, Britain’s top Brexiteer. (Let’s say that sotto voce, unlike The Sun, which put that on its front page.) As has been observed, she’s a grandmother who didn’t go to university: Her demographic is almost 100 percent pro-Brexit.

is for the refugees from the Middle East and Africa, whose irruption onto Europe’s territory (and into Europe’s imagination) put the fear of God into those voters who might, with only some unkindness, be called Little Englanders. Lost in the hysterical debate over the incoming “swarms” — other collective nouns were seldom used — was the fact that no country was more difficult to reach, and be admitted to, than Britain.

is for the threat of an independent Scotland, which is what you get, in political math, when you subtract the U.K. from the EU. Nicola Sturgeon, the Scottish nationalist leader, has called for a second referendum on the question of independence. But she’ll have to watch out for Spain, which doesn’t look kindly on separatist antics and would be unlikely to welcome a sovereign Scotland into the EU. (S is also for Tim Shipman — “Shippers” to his friends and colleagues — who has written the best book on Brexit, “All Out War.” His delivery of 624 footnoted pages just two months after the referendum was a feat almost as remarkable as Brexit itself.)

is for the British tabloids, those Europhobic dogs of war that snarled and bit their way to victory. “Call that a deal, Dave?” sneered the Daily Mail, after Cameron had wrung an important concession out of the EU that could have served as a basis for a new relationship with Europe. Nothing short of Brexit was ever enough for the editors, who were giddy at the prospect of leaving a union they loathed. One question remains: What on earth will they write about once the EU isn’t around to pillory?

is for universal welfare, Britain’s benefits system, which sat uncomfortably alongside mass immigration in the public imagination. If the U.K. had had a system of contributory benefits, the “scrounging foreigners” argument might never have cropped up.

is for Verhofstadt’s veto, the power of non-consent that’s in the hands of Guy V., the European Parliament’s Brexit coordinator. He has the power to scupper any agreement that the U.K. and the EU might reach. Being a pragmatic dealmaker by nature, however, it would take something extraordinary for him to play spoiler. Predictions of this sort are, of course, a game played only by mugs.

is for the weeping and wailing, and wringing of hands among Britain’s cosmopolitan elites, who wonder how the oiks and the unwashed could have destroyed their country’s perfectly lovely European idyll. The matter will, no doubt, be debated for generations.

is for xenophobes and xenophiles, which is how those who voted Leave and Remain characterize each other. Lost in all the name-calling are, as usual, the important nuances of political difference that are impossible to capture in pithy political invective.

is for Y Gwyll, a Welsh television program set to suffer a calamitous loss of public funding when Brexit occurs and it loses access to the EU’s Creative Europe program. Wales voted 52.5 percent to 47.5 percent to leave the EU, so they should have seen it coming.

is for zero, the amount that the most vociferous Brexiteers in Parliament say Britain will owe the EU as part of an “exit bill.” European leaders, such as Austrian Chancellor Christian Kern, have asserted that Britain could have to cough up as much as €60 billion as alimony when the divorce goes through. But as one influential MP told POLITICO earlier this month, “Legally we owe nothing.”

Tunku Varadarajan, a contributing editor at POLITICO, is the Virginia Hobbs Carpenter Fellow in Journalism at Stanford University’s Hoover Institution.