It's been a long long year of flag talk.

We've yelled at each other over the $26 million pricetag, the contentious longlist of 40 flags, the even more contentious list of four flags, the late-in-the-game addition of the Red Peak option after urban outcry, and a whole bunch of conspiracy theories to boot.

READ MORE:

* John Key reveals which flag design he's most keen on

* Comment: The folly of finding a new flag

* RSA divided over organisation's bid to upset flag referendum

* Red Peak: flag or a company logo?

* Final four NZ flag designs unveiled

* The flag debate: full coverage

Final five New Zealand flags: Which is your favourite? Share your stories, photos and videos. Contribute

But unless you submitted a flag for contention, you haven't had a chance to have your say yet. That process - the actual referendum - is about to begin. But the two-step preferential voting process isn't all that simple.

WHAT'S THE ACTUAL VOTING PROCESS?

First things first - there are two votes, one from late November to early December, and one in March of 2016.



Both are mail referendums, so you don't need to go to a booth or anything, and you have plenty of time to mull your decision. Unlike many other referendums, these ones are binding - they aren't suggestions to the government, they are orders. You should get your first voting paper by Friday the 27th of November at the latest, and you'll need to mail it back by Tuesday 8 December.



The first referendum asks you to rank the five alternate flags in order of preference. It'll look like this.







Here's where things get a little bit complex. This first vote isn't you voting to change the flag. That comes in March. This is you voting for which of these five options you think would be the best replacement - regardless of whether you think the flag should change or not.



In the second referendum in March, whichever flag wins the first referendum will go up against our current flag in a plain old "first past the post" mail referendum. Whichever flag wins the most votes wins. Easy.



WAIT, I HAVE TO RANK THEM?



Yup, this isn't just an up or down which flag gets the highest percentage of votes kind of thing. Instead, it works on preferential voting. You rank the flag you want the most as your number 1 flag, then rank as many other flags as you want in descending order.



Preferential voting works by knocking off the least popular flags. If one flag gets 50 per cent or more of the "1" votes, it wins. But if none of them do, the flag with the least number of "1" votes is knocked out of the running. The voters who put that losing flag as their number 1 have their number 2 votes for other flags upgraded to number 1s and distributed out to the other candidates. If that bumps one up past 50 per cent, it wins. If not, the flag with the second least amount of 1 votes is knocked out, and so on.



A bit confused? Here's a quick example. New Zealand is suddenly hit by a meteor leaving just 20 of us alive, but we still decide to vote for the flag for some reason.







Nine people vote for the koru as their number one flag, four for red peak, three each for both of those colourful fern designs, and just one for the black and white fern.



None of the flags have received enough first choice votes to win 50 per cent - that would be 10 - so the black and white fern is cut out of the running. However, that black and white fern voter was a big fan of monochrome, so put the koru as their number 2. That vote is now upgraded to a number 1, and the koru now has 10 votes, or 50 per cent of the total, and wins.



Phew, okay.

DO I NEED TO DO ANYTHING OR WILL THE LETTER JUST COME TO ME?

You need to be enrolled to vote! There isn't any special flag specific enrolment, you're regular old election enrolment is a-okay. You should already be: it's actually illegal to not be enrolled.

You can check if you have enrolled here. Even if you know you were enrolled, you might want to check to make sure the address is still current. If you're not enrolled, it isn't all that hard - you can do it online here.

WHY THE TWO PART VOTE? DOESN'T THAT MAKE IT WAY MORE EXPENSIVE?

Yup, but it's also the only way a new flag has any chance. The logic the panel are operating under assumes that if we offer five new flags AND keeping the old flag as options in one vote, there's no way any of the new flags will rise above the fray to take on the tried and true. Polling confirms this.

Someone who hates four of the new flags but quites like one might still vote to keep the old flag, as they would rather stick with the status quo than risk one of the ones they hate winning.

With a two part process one flag gets to emerge as the only alternative option, and we all get a few months to think about just that flag v this flag.

BUT I WANT TO KEEP THE CURRENT FLAG. SHOULD I SPOIL MY BALLOT?

Depends on the veracity of your feelings, really, but the flag panel would prefer that you didn't. If you really really really despise the idea of the flag changing in any way, so much so that you hate all the five alternative options equally, then you might want to spoil your ballot in some way. The RSA are encouraging people to write "I vote to keep the current flag," but as informal votes are generally counted as a block, you could get much more creative.

There's also more subtle ways of gaming the process in favour of the current flag. In the latest polling the koru flag is the least popular. One assumes if enough anti-new-flag voters proposed it as the alternative the new flag would romp home in the second referendum.

But should you? This is, as the panel keeps saying, probably a once in a lifetime opportunity. If the flag does change, don't you want a part in deciding just what it changes to? Nothing is stopping you from voting for your favourites in the first referendum then solidly voting against that same favourite in the second.

SO SAY WE DO PICK A NEW FLAG IN MARCH, HOW DOES THAT LIKE, HAPPEN?

Nothing is quite certain here, but the government's regulatory statement suggests we would see a transition period of around 12 months. Ships would be given another six months. Flags on items like driver's licenses and military uniforms would probably only be changed when those items are replaced for other reasons, so that could take quite a while. It would likely still be legal to fly the old flag as a recognised historic flag.

As for costs, the government would not reimburse any private companies or individuals updating their flags. The costs to governmental organisations would be in the low single millions - far less than the $26m referendum process.

WOULD A NEW FLAG CHANGE ANYTHING ELSE IN NEW ZEALAND'S CONSTITUTION OR GOVERNMENT?

No.