Five years of intense diplomatic training have not been lost on Julie Bishop.

The long flights, the sleepless nights, the interminable state dinners pretending that Ambassador X is fascinating company, the multiple instances of cheerfully not minding when some foreign leader mistakes her for the wife of the Australian foreign minister; all of it has worked.

From the hellish inferno of politesse that is the foreign affairs portfolio has emerged — phoenix-like, diamond-hard and glittering — a creature so confident in her diplomatic skills that she can stand in Parliament and declare with an absolutely straight face, that the last few weeks has made her certain that the Government will be returned, and that's why she's quitting.

This is after, one hardly needs to be reminded, a fortnight in which the Government has been worn like a pair of pants on the floor of the House of Representatives, the Finance Minister has lost control of his own credit card, while half a billion of taxpayers' pineapples have been handed over to a security company registered to a Singapore PO box.

"Pull the other one, it's got Manolos on it," would be the first thought of many listening to the speech in which, this afternoon, Ms Bishop relinquished her 21-year political career.

But if Ms Bishop has established anything over that career, especially the last few years, it's that she has earned the right to do what she bloody well likes.

Eleven years she spent as the deputy leader of the Liberal Party, scooting around the country visiting the electorates of her colleagues.

Sorry, this video has expired Julie Bishop calls out "appalling" behaviour in parliament

That's a year for every vote she got when she ran for the leadership, despite being hands-down the most recognisable and popular candidate.

There were strategic reasons why that vote was so low, but for a woman who has practically held the party together over more than a decade, soothed the backbench and deployed energy and emotional intelligence through the leaderships of four different men, you could understand why even the most diplomatic of deputies would feel a bit miffed.

Not that you saw even a trace of miffedness on display today.

Australia's former chief diplomat was charm itself as she descanted smoothly — without the benefit of notes — on her pride in and respect for the Australian people, the Australian Parliament, her colleagues and so forth.

More to Bishop's farewell than meets the eye

But Ms Bishop speaks, like all good diplomats, in code.

She is also a self-confessed student of Madeleine Albright, the Clinton-era secretary of state who used brooches to send discreet messages to her allies and oppressors.

"Read My Pins," was the title of Albright's memoir, in which she described wearing bug pins when she feared she was being bugged by Russian spies, a snake pin after Saddam Hussein's spokesman called her a "serpent", a mushroom pin to signal to journalists that secret talks would have to stay secret a little longer.

Ms Bishop has followed and been inspired by the career of US diplomat Madeleine Albright. ( United States Department of State )

Ms Albright was the only woman on the UN Security Council during a dangerous time in world diplomacy, just as Ms Bishop was the only woman in the first Cabinet of this Coalition Government.

Both of them had to make their own fun.

So which coded messages were in the final speech to the Parliament of Julie Isabel Bishop, Member for Curtin?

Well, crass as it is to concentrate on a lady's wardrobe, it is impossible to avoid comment on the former foreign minister's choice of frock for the announcement.

Pure, dazzling white. The choice of the suffragettes, the choice of Democratic women lodging a visually-arresting protest against Donald Trump during the recent State of The Union, the choice indeed of Joan of Arc as she rode into battle.

Joan's was a gift from Charles VII; Julie's was probably more likely to be Armani, but there's no doubt that white is the colour for women of courage who are not afraid either of male-dominated environments or of eating a tomato sandwich at work.

Also, listen carefully to the remarks about the seat of Curtin.

"I have been contacted by a number of talented, indeed extraordinary, people, including women, who have indicated to me that should I not reconsider the seat of Curtin, they would seek preselection from the Curtin division of the Liberal Party for that seat ... It is time for a new member to take my place."

Dressed in white, Ms Bishop walks out of Parliament on her own terms. ( ABC News: Matt Roberts )

Now it's no secret that Attorney-General Christian Porter has been fretting a bit about his super-ticklish marginal seat, and would much prefer the security of a bolt-hole like, say, Curtin, which Ms Bishop has over 21 years built (as she delicately pointed out in her speech) into a stylish Liberal fortress of more than generous margin.

Ms Bishop's late call has made that potential transfer very difficult.

And her pointed mention of talented female contenders makes the translation quite clear: "Preselect a chick for my seat, fellas, or I'm going to come back and haunt you like a gorgeous, perfectly-shod demon".

For a woman who's always denied being a feminist, she sails dangerously close to the wind.