Everything you need to know about tonight's roll call at the RNC

Delegates will vote tonight to officially nominate Donald Trump as the Republican Party's nominee for president. Here's everything you need to know:

What Are the Basics?

The afternoon session will gavel in shortly after 5:30 p.m., with the roll call coming after 6:00 p.m. The convention secretary goes one-by-one through the list of states alphabetically. The chair of each delegation will briefly tout their state before announcing their state's vote total. It should last over an hour. Since nearly all of the delegates are bound, we know that Trump will win a majority of delegates. But anti-Trump backers may still stir up trouble on the floor by trying to go rogue.

So When Will Trump Actually Become 'the Nominee'?

Not until Thursday night. Trump will not officially become the Republican Party's nominee for president until he accepts the nomination, which is slated to occur as part of his major speech on Thursday night, according to the RNC counsel's office. It's like a marriage: You need an "I do" from both sides to become the nominee. The Republican convention will offer the nomination when the delegates vote, and Trump needs to accept it.

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Give Me the Step by Step:

First, Trump must demonstrate the support of a majority of delegates in eight states in order to be nominated on the floor. A supporter will give a short speech nominating him and at least one supporter will give a short speech to second.

The secretary starts a roll call vote of the states, calling out the name of the state and its number of delegates in alphabetical order.

States are allowed to pass. The secretary will go back through the names of the states that were skipped at the end.

Each state will announce the aggregate vote from their state as the delegates are bound. The secretary (or assistant secretary) will repeat back the tally and record it.

This year, the secretary will repeat back and record the votes for all candidates, including those not placed in nomination. This is different than in 2012, when only Romney's votes were repeated back and counted. It's a nod of inclusion.

Once every state has voted, the convention chair will announce the tally for each candidate and announce that Trump has garnered the support of a majority of delegates eligible under the call.

Which States Will 'Pass' During the Roll Call Vote?

States are allowed to skip their turn if they choose. On the first round of the roll call, we expect some anti-Trump states like Colorado may skip their turn. We also expect Trump's home state of New York to pass on the first time through the list, because they want to be the state to put Trump over the 1,237 magic number. The secretary will return to states that skipped at the end.

When Will Trump Officially Clinch the Nomination?

We expect Trump to approach 1,237 votes around Pennsylvania in the alphabetical, state-by-state vote. At that point, the rest of the states down the alphabet will likely skip their turns. The list will then circle around to the top, going back through the list with the states that skipped.

We expect New York will put Trump over the magic number of 1,237 votes. If any anti-Trump states also skipped on the second time through the roll call, the roll call will begin a third time, naming any state that passed twice.

What Can Anti-Trump Forces Do?

Delegates are allowed to protest if they think their vote wasn't announced correctly. Anti-Trump efforts say there will be delegates who believe they should be unbound who will try to raise trouble if their vote is counted for Trump anyway.

(It's also still possible that Ted Cruz could be placed in nomination if signatures are collected from a majority of eight states. This is unlikely, especially given how Trump staffers stripped votes from an effort to force a roll call vote yesterday.)

What About the Vice President?

There will not be a state-by-state vote for vice president. Pence will be nominated "by acclamation" -- which basically means just an up-or-down vote. This is normal. This works because we expect Pence will be the only candidate placed in nomination, that is, able to demonstrate the support of a majority of delegates from eight states.