In the film, the infamous hand-scribbled note that Queensbury handed to the hall porter at Wilde's club read, "To Oscar Wilde posing as a Sodomite". In reality, the marquess wrote "To Oscar Wilde posing Somdomite", misspelling the crucial word that goaded Wilde into suing him for libel.
When the Marquis of Queensberry writes his insulting note - "To Oscar Wilde, posing as a Sodomite" - the club desk clerk to whom he has given it consults a dictionary for the meaning of the word. The definition is clearly cut and pasted from another source, and in addition, it has been cut and pasted, perhaps deliberately, into the middle of the dictionary's definition for "sentimental."
When Oscar Wilde is asked to state his name at the beginning of his trial testimony, he incorrectly replies "Oscar O'Flahertie Fingal Wills Wilde," transposing the names O'Flahertie and Fingal. The correct name, mentioned several times a few minutes before in the reading of the charge by the clerk of the court, is Oscar Fingal O'Flahertie Wills Wilde.