The White House on Thursday announced that the G-7 group of nations will hold its 2020 meeting at Trump National Resort in Florida, reviving talk that the event will benefit President Donald Trump and his family, in violation of the Constitution’s Emolument Clause.

Here’s a quick explainer on emoluments, the clause, and the controversy surrounding Trump.

What is an emolument?

Barron’s Legal Guides Law Dictionary defines an emolument as “profit derived from office, employment, or labor, including salary, wages, fees, rank and other compensation. ”

According to the Dictionary of Word Origins by John Ayto, emolument is derived from the Latin emolumentum, meaning “a fee paid to a miller for grinding grain.” It, in a way, is comparable to the term salary, which originally meant “a payment for salt. ”

What is the Emolument Clause?

The clause is found in Article I, Section 9, Clause 8 of the U.S. Constitution.

No Title of Nobility shall be granted by the United States: And no Person holding any Office of Profit or Trust under them, shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince or foreign State.

Legal scholars say the clause’s purpose is to protect the United States’ republican character from corrupting foreign influences. It essentially bans the president and other federal officials from accepting gifts or payments from foreign governments without congressional consent.

Violating the clause is generally held to be an impeachable offense.

How has Trump opened himself to charges of violating the clause?

Since taking office, the president has not divorced himself from his businesses, such as by placing them in a blind trust. Instead, Trump says, he has turned over operations of the business to his children, while still retaining ownership. At the same time, Trump has promoted his properties while in office, including suggesting Doral for the G-7 Summit.

Trump has repeatedly denied profiting from his office.

Has this issue come up before?

A lawsuit filed by the Democratic attorney generals of Maryland and the District of Columbia alleges that Trump has violated the clause because of ownership of the Trump International Hotel in Washington. Since his election, the hotel has become a favored lodging and event space for some foreign officials visiting the capital. The lawsuits argue that leaves the president open to inducements from foreign governments seeking to curry favor.

The full 4th U.S. Circuit Court of Appeals in Richmond, Va., will hear arguments on the suit Dec. 12.

Two similar pending lawsuits have been filed separately by 200 Democratic lawmakers and the Washington-based advocacy group Citizens for Responsibility and Ethics.