Capo di tutt'i capi or capo dei capi is Italian for "boss of all bosses" or "boss of [the] bosses".
 It is a phrase used mainly by the media, public and the law enforcement community to indicate a supremely powerful crime boss in the Sicilian or American Mafia who holds great influence over the whole organization.
The Irish Question was a phrase used mainly by members of the British ruling classes from the early 19th century until the 1920s.
 It was used to describe Irish nationalism and the calls for Irish independence.
Wabenzi is an Anglicization of the pejorative Bantu colloquialism WaBenzi, originally used in Kenya to refer to members of the new ruling class that superseded the colonial regime, that has come to refer to the new ruling class in any post-colonial African country.
 The term usually refers to a corrupt government official, or family member of one, and derives from their being seen as driving an imported car.
 "Wa" is a prefix that refers to people in some Bantu languages; "benzi" comes from Mercedes-Benz, a car perceived as prestigious.
 The Anglicized form is more common than the original Bantu WaBenzi.
The American Ruling Class is a 2005 dramatic documentary film written by Lewis H. Lapham and directed by John Kirby that "explores our country’s most taboo topic: class, power and privilege in our nominally democratic republic."
 It seeks to answer the question, "Does America have a ruling class?"
 Its producers consider it the first "dramatic-documentary-musical."
 A rough-cut of the film was shown at the 2005 Tribeca Film Festival, the final version of the film was shown on the Sundance Channel in July 2007, and it had its theatrical premiere at the Brooklyn Academy of Music in April 2008.
The Ruling Class is a 1972 British black comedy film.
 It is an adaptation of Peter Barnes' satirical stage play "The Ruling Class" which tells the story of a paranoid schizophrenic British nobleman (played by Peter O'Toole) who inherits a peerage.
 The film co-stars Alastair Sim, William Mervyn, Coral Browne, Harry Andrews, Carolyn Seymour, James Villiers and Arthur Lowe.
 It was produced by Jules Buck and directed by Peter Medak.
Proof by intimidation (or argumentum verbosium) is a jocular phrase used mainly in mathematics to refer to a style of presenting a purported mathematical proof by giving an argument loaded with jargon and appeal to obscure results, so that the audience is simply obliged to accept it, lest they have to admit their ignorance and lack of understanding.
A slogan is a memorable motto or phrase used in a clan, political, commercial, religious, and other context as a repetitive expression of an idea or purpose, with the goal of persuading members of the public or a more defined target group.
 The "Oxford Dictionary of English" defines a slogan as "a short and striking or memorable phrase used in advertising."
 (Stevenson, 2010) A slogan usually has the attributes of being memorable, very concise and appealing to the audience.
 (Lim & Loi, 2015).
 These attributes are necessary in a slogan, as it is only a short phrase.
 Therefore, it is necessary for slogans to be memorable, as well as concise in what the organisation or brand is trying to say and appealing to who the organisation or brand is trying to reach.
In Marxist philosophy, cultural hegemony is the domination of a culturally diverse society by the ruling class who manipulate the culture of that society—the beliefs, explanations, perceptions, values, and mores—so that their imposed, ruling-class worldview becomes the accepted cultural norm; the universally valid dominant ideology, which justifies the social, political, and economic "status quo" as natural and inevitable, perpetual and beneficial for everyone, rather than as artificial social constructs that benefit only the ruling class.
The Irish Convention was an assembly which sat in Dublin, Ireland from July 1917 until March 1918 to address the "Irish question" and other constitutional problems relating to an early enactment of self-government for Ireland, to debate its wider future, discuss and come to an understanding on recommendations as to the best manner and means this goal could be achieved.
 It was a response to the dramatically altered Irish political climate after the 1916 rebellion and proposed by David Lloyd George, Prime Minister of the United Kingdom of Great Britain and Ireland, in May 1917 to John Redmond, leader of the Irish Parliamentary Party, announcing that 'Ireland should try her hand at hammering out an instrument of government for her own people'.
The Korean ruling class refers to persons in contemporary South Korean society known for holding multiple offices in government, education, and the chaebol, stressing degrees from elite (especially American) universities, and reserving important positions for one another and their family members.
 According to social theory, this class protects and perpetuates itself by valuing family background, prestigious education, loyalty to friends/classmates/hometown, and chaebol wealth, while those excluded from the class are unable to access these prerequisites for class membership.
 Leaders of admired institutions, such as Samsung, are often insulated from criticism, but there is occasionally popular backlash against the perceived abuses of the elite class, such as the Korean Air "nut rage" scandal.

Question: What phrase used mainly by the members of the British ruling class was addressed by the Irish Convention?
Answer: Irish question